Add user to a BP group automatically based on joined membership WPMU membership2

code.php

<?php

add_action( 'ms_model_relationship_create_ms_relationship_before', 'ms_controller_member_assign_memberships_done_cb', 99, 4 );
function ms_controller_member_assign_memberships_done_cb( $membership_id, $user_id, $gateway_id, $move_from_id ) {
    
    // Create an array with membership IDs and group IDs like:
    /*$array = array(
        'membership_id' => 'group_id',
        'membership_id' => 'group_id',
        'membership_id' => 'group_id'
    );*/
    
    $config = array(
        '11' => 4,
        '19' => 3,
        '20' => 2
    );
    
    groups_join_group( $config[$membership_id], $user_id );
}