Use setting field value in field query_args

Hello!

I've created a custom relationship between WooCoomerce products and pages:

    add_action('mb_relationships_init', function() {
      MB_Relationships_API::register(array(
        'id' => 'gg_products_to_page',
        'from' => 'product',
        'to' => array(
          'post_type' => 'page',
          'field' => array(
            'query_args' => array(
              'post_parent' => (int) rwmb_meta('gg-packages-parent-page', array('object_type' => 'setting'), 'ggbox_settings')
            ),
            'clone' => false
          )
        ),
        'reciprocal' => true
      ));
    });

The problem: rwmb_meta in this hook always returns false. 🙁 How can I properly adjust the code to use a predefined setting variable in relationship settings? If I call the rwmb_meta() function elsewhere, it works and returns the currect setting value.

Thanks!