Get Metabox Group subfield values from serialized array

Hi there,
how can I get 'subfield' values from the serialized array of a Metabox Field Group - outside of pages and posts, where the traditional:

`get_post_meta(get_the_id(), 'meta-key', true);'

will NOT work.

OR

$group_values = rwmb_meta( 'group_id' ) ?: [];
foreach ( $group_values as $group_value ) {
    $value = $group_value[ $sub_field_key ] ?? '';
    echo $value; // Display sub-field value
}

wiLl also NOT work?

Any help appreciated 🙂