Syncing Group Taxonomy Advanced Field with a Taxonomy Field

Hello,

You are correct. It is possible to set the post terms based on the taxonomy_advanced field value in a group. If you are familiar with coding you can create some lines of code to set the post terms. Please read more on the documentation
https://docs.metabox.io/actions/rwmb-after-save-field/
https://developer.wordpress.org/reference/functions/wp_set_object_terms/

Hello,

For example, I have a taxonomy field and a taxonomy_advanced subfield in a group field, like this

$meta_boxes[] = [
    ...
    'fields'   => [
        [
            'name'       => __( 'Taxonomy', 'your-text-domain' ),
            'id'         => 'taxonomy_field',
            'type'       => 'taxonomy',
            'taxonomy'   => ['drink-recipe'],
            'field_type' => 'select_advanced',
        ],
        [
            'name'   => __( 'Group', 'your-text-domain' ),
            'id'     => 'group_field',
            'type'   => 'group',
            'fields' => [
                [
                    'name'       => __( 'Taxonomy Advanced', 'your-text-domain' ),
                    'id'         => 'taxonomy_advanced_field',
                    'type'       => 'taxonomy_advanced',
                    'taxonomy'   => ['drink-recipe'],
                    'field_type' => 'select_advanced',
                ],
            ],
        ],
    ],
];

Then the code to set the post term from the taxonomy_advanced field would be:

add_action( 'rwmb_group_field_after_save_field', function ( $null, $field, $new, $old, $object_id ) {
    $term_id = (int)$new['taxonomy_advanced_field'];  
    wp_set_object_terms( $object_id, $term_id, 'drink-recipe' ); 
}, 10, 5 );

This is the example code, if it does not work on your site, please contact us with the link below and request a customization service, our development team will help you to check the issue.
https://metabox.io/contact/