MB Group

MB Group helps you to organize custom fields into repeatable and collapsible groups. You can use this extension to group related fields into one group to create hierarchy. You can clone the whole group, or sub-group. There's no limitation on the nesting level.

Tutorial

If this is your first time using MB Group, start with this beginner-friendly guide:

👉 How to Create a Group of Custom Fields with MB Group

The rest of this page is a detailed reference. Feel free to come back whenever you need to check specific settings or examples.

Settings

MB Group introduces a new field type: group. Here are its available settings:

Name	Description
name	Field label. Works like other fields. Optional.
id	Field ID, used to store the group's values (including all sub-fields).
type	Must be set to group.
fields	An array of sub-fields. Each sub-field is declared like a normal field.
clone	Makes the group clonable (repeater).
sort_clone	Allows drag-and-drop reordering of clones. true or false.
collapsible	Makes the group collapsible. true or false (default false). Optional.
save_state	Save the collapse/expand state? true or false (default false). Optional.
default_state	Default state when the page loads: collapsed or expanded (default).
group_title	Title of collapsible groups. See Collapsible Groups.

Example: Simple group with sub-fields

To add a group, create a field with type => group and list its sub-fields inside the fields parameter:

add_filter( 'rwmb_meta_boxes', function ( $meta_boxes ) {
    $meta_boxes[] = [
        'title'  => 'Album Tracks',
        'fields' => [
            [
                'id'         => 'standard',
                'type'       => 'group',  // Group!
                'clone'      => true,     // Clone whole group?
                'sort_clone' => true,     // Drag and drop clones to reorder them?

                // List of sub-fields.
                'fields'     => [
                    [
                        'name' => 'Track name',
                        'id'   => 'text',
                    ],
                    [
                        'name' => 'Release Date',
                        'id'   => 'date',
                        'type' => 'date',
                    ],
                    [
                        'name'    => 'Genre',
                        'id'      => 'genre',
                        'type'    => 'select_advanced',
                        'options' => [
                            'pop'  => 'Pop',
                            'rock' => 'Rock',
                        ],
                    ],
                ],
            ],
        ],
    ];
    return $meta_boxes;
} );

Here's how it looks:

Nested groups

You can even put a group inside another group, creating multi-level nested structures:

add_filter( 'rwmb_meta_boxes', function ( $meta_boxes ) {
    $meta_boxes[] = [
        'title'  => 'Multi-level nested groups',
        'fields' => [
            [
                'id'     => 'group',
                'type'   => 'group',
                'fields' => [
                    [
                        'name' => 'Text',
                        'id'   => 'text',
                    ],
                    [
                        'name'   => 'Sub group',
                        'id'     => 'sub_group',
                        'type'   => 'group',
                        'fields' => [
                            // Normal field (cloned)
                            [
                                'name'  => 'Sub text',
                                'id'    => 'sub_text',
                            ],
                        ],
                    ],
                ],
            ],
        ],
    ];
    return $meta_boxes;
} );

✅ MB Group supports unlimited nesting levels.

Collapsible groups

Want to make your groups collapsible? Just set:

'collapsible' => true

Collapsible groups support extra settings:

Name	Description
save_state	Save the expanded/collapsed state? true or false. Default false.
default_state	Default state when the page loads: collapsed or expanded (default).
group_title	Title of each group item. Can include static text, clone index, or sub-field values.

Dynamic group titles

You can mix static text, clone index, and sub-field values in the group_title:

'group_title' => 'Branch {#}: {sub_field_1} - {sub_field_2}',

• {#} → group index (if clonable).
• {sub_field_id} → value of a sub-field.
• Combine as many as you need.

Example: Collapsible group with nested groups

add_filter( 'rwmb_meta_boxes', function ( $meta_boxes ) {
    $meta_boxes[] = [
        'title'  => 'Company Branches',
        'fields' => [
            [
                'id'          => 'g1',
                'name'        => 'Branches',
                'type'        => 'group',
                'clone'       => true,
                'collapsible' => true,
                'group_title' => '{name}', // ID of the subfield

                'fields' => [
                    [
                        'name' => 'Name',
                        'id'   => 'name',
                    ],
                    [
                        'name' => 'Address',
                        'id'   => 'address',
                    ],
                    [
                        'id'          => 'contacts',
                        'type'        => 'group',
                        'clone'       => true,
                        'collapsible' => true,
                        'group_title' => '{person}',
                        'fields'      => [
                            [
                                'id'   => 'person',
                                'name' => 'Person',
                            ],
                            [
                                'id'   => 'phone',
                                'name' => 'Phone',
                            ],
                        ],
                    ],
                ],
            ],
        ],
    ];

    return $meta_boxes;
} );

Data storage

• Group values are saved as an array of sub-field values (including nested groups).
• Data is stored in the database as a serialized array.
• Sub-field data is saved "as is" (no extra sanitizing or transformation).

caution

It's important to understand that when a field is placed inside a group, its value is saved exactly as it is. The plugin does not apply any sanitization or transformation when saving or retrieving field values. This behavior helps avoid heavy processing, especially when working with complex structures or deeply nested groups.

Example:

If you add a date field inside a group and set a save_format that differs from the display format, the save_format will not be applied. In this case, the saved value will always match the displayed value - no formatting changes are made during saving.

Getting sub-field values

To retrieve group data, use rwmb_meta():

$group_value = rwmb_meta( 'group_id' ) ?: [];

This returns an associative array of sub-field IDs and values:

[
    'sub_field_1' => 'value 1',
    'sub_field_2' => 'value 2',
]

To access a sub-field:

$value = $group_value['sub_field_1'] ?? '';
echo $value;

If the group is cloneable, rwmb_meta() returns an array of groups, like this:

[
    [ 'sub_field_1' => 'value 1', 'sub_field_2' => 'value 2' ],
    [ 'sub_field_1' => 'value 3', 'sub_field_2' => 'value 4' ],
]

Loop through them:

$groups = rwmb_meta( 'group_id' ) ?: [];
foreach ( $groups as $group ) {
    echo $group['sub_field_1'] ?? '';
}

Example: Contacts group

Registering a group of contacts:

add_filter( 'rwmb_meta_boxes', function ( $meta_boxes ) {
    $meta_boxes[] = [
        'title'  => 'Contacts',
        'fields' => [
            [
                'id'     => 'contacts',
                'type'   => 'group',
                'clone'  => true,
                'fields' => [
                    [ 'id' => 'name',  'name' => 'Name' ],
                    [ 'id' => 'email', 'name' => 'Email' ],
                    [ 'id' => 'phone', 'name' => 'Phone' ],
                ],
            ],
        ],
    ];
    return $meta_boxes;
} );

Displaying contacts in single.php:

$contacts = rwmb_meta( 'contacts' ) ?: [];
foreach ( $contacts as $contact ) {
    echo '<div class="contact">';
    echo '<h4>Contact info</h4>';
    echo '<p><strong>Name:</strong> ' . $contact['name'] . '</p>';
    echo '<p><strong>Email:</strong> ' . $contact['email'] . '</p>';
    echo '<p><strong>Phone:</strong> ' . $contact['phone'] . '</p>';
    echo '</div>';
}

Outputting groups with page builders

• ✅ Elementor and Oxygen: can output group sub-fields directly.
• ❌ Other builders (e.g., Beaver Builder, Divi): use an MB View or a shortcode

Example shortcode (group with title, images, and desc):

add_shortcode( 'my_group', function() {
    $group = rwmb_meta( 'group_field_id' );
    if ( empty( $group ) ) {
        return '';
    }

    $output = '';

    // Title
    $title = $group['title'] ?? '';
    $output .= $title ? '<h3>' . $title . '</h3>' : '';

    // Images
    $image_ids = $group['images'] ?? [];
    if ( $image_ids ) {
        $output .= '<div class="images">';
        foreach ( $image_ids as $id ) {
            $image = RWMB_Image_Field::file_info( $id, ['size' => 'thumbnail'] );
            $output .= '<img src="' . $image['url'] . '">';
        }
        $output .= '</div>';
    }

    // Description
    $desc = $group['desc'] ?? '';
    $output .= $desc ? wpautop( $desc ) : '';

    return $output;
} );

Usage: Add [my_group] into your post/page content or page builder module.

Sub-field values

rwmb_meta() returns raw values for sub-fields. It does not format them like it does for individual fields.

Field type	Value
taxonomy, user, post	Object ID(s)
File & image fields	Attachment ID(s)
map, osm	"latitude,longitude,zoom"
oembed	URL
wysiwyg	Raw content (no <p></p>)

Example: getting image info from sub-fields:

$group = rwmb_meta( 'group_id' );
$image_ids = $group['image_key'] ?? [];
foreach ( $image_ids as $id ) {
    $image = RWMB_Image_Field::file_info( $id, ['size' => 'thumbnail'] );
    echo '<img src="' . $image['url'] . '">';
}

These are some helper functions that you can use to retrieve more info:

Field type	Helper function(s)
image, image_advanced, image_upload, single_image	wp_get_attachment_image_src()
-	wp_get_attachment_image_url()
-	RWMB_Image_Field::file_info( $image_id, $args ); (where $args is an array and accepts only size attribute)
file, file_advanced, file_upload	get_attached_file()
-	RWMB_File_Field::file_info( $image_id );
oembed	RWMB_OEmbed_Field::get_embed( $url );
taxonomy, taxonomy_advanced	get_term()
user	get_userdata()
post	get_post()
wysiwyg	wpautop()

Read more on how field values are saved into the database.

Setting default values

There are 2 ways to set default values:

• Per sub-field → using std on each field.
• Whole group → using std on the group.

Per sub-field

add_filter( 'rwmb_meta_boxes', function( $meta_boxes ) {
    $meta_boxes[] = [
        'title' => 'Test Group Default Value',
        'fields' => [
            [
                'type' => 'group',
                'id'   => 'group',
                'fields' => [
                    [
                        'id'   => 'name',
                        'name' => 'Name',
                        'std'  => 'My Name',
                    ],
                    [
                        'type' => 'email',
                        'id'   => 'email',
                        'name' => 'Email',
                        'std'  => '[email protected]',
                    ],
                ],
            ]
        ],
    ];
    return $meta_boxes;
} );

Result:

Whole group

Instead of setting std for each field, define an array for the group:

add_filter( 'rwmb_meta_boxes', function( $meta_boxes ) {
    $meta_boxes[] = [
        'title' => 'Test Meta Box',
        'fields' => [
            [
                'type' => 'group',
                'id'   => 'group',
                'fields' => [
                    [
                        'id'   => 'name',
                        'name' => 'Name',
                    ],
                    [
                        'type' => 'email',
                        'id'   => 'email',
                        'name' => 'Email',
                    ],
                ],

                'std' => [
                    'name'  => 'My name',
                    'email' => '[email protected]',
                ],
            ]
        ],
    ];
    return $meta_boxes;
} );

If the group is cloneable, std should be an array of group values:

'std' => [
    [ 'name' => 'Name 1', 'email' => '[email protected]' ],
    [ 'name' => 'Name 2', 'email' => '[email protected]' ],
],

And here is the result:

See this video for demonstration:

Changing clone button text

Change the button label with add_button:

[
    'type'       => 'group',
    'name'       => 'Tracks',
    'id'         => 'tracks',
    'add_button' => 'Add another track',
    'fields'     => [
        // Sub-fields here.
    ],
],

Clone default values

When cloning a group:

• If the group has 'clone_default' => true, all sub-fields will use their default values.
• If a sub-field is cloneable, its own clone_default takes priority.

Learn more: clone_default parameter

Changing group titles with JavaScript

You can filter group titles with JavaScript:

jQuery( function() {
    // Change "myVendor/myPlugin" to your unique namespace
    rwmb.hooks.addFilter( 'group.title', 'myVendor/myPlugin', function( title ) {
        // Change the title and return the value here.
        return title + ' Some random string';
    } );
} );

Known issues

• When cloning nested groups, input id attributes may change in unpredictable ways. Avoid relying on them in custom JavaScript.
• For wysiwyg fields inside cloneable groups, don't end the field ID with _{number} (like _12). This pattern is reserved by the clone script. Use another format instead.