Yes, I used the Builder add-on, and this is the code it gave me.
add_filter( 'rwmb_meta_boxes', 'your_prefix_register_meta_boxes' );
function your_prefix_register_meta_boxes( $meta_boxes ) {
$meta_boxes[] = array (
'title' => 'Premium Categories',
'id' => 'premium_categories',
'autosave' => true,
'fields' => array(
array (
'id' => 'premium_categories',
'type' => 'taxonomy',
'name' => 'Sections',
'desc' => 'Choose which types of articles you want to appear in your custom feed.',
'taxonomy' => 'category',
'field_type' => 'select_advanced',
'multiple' => true,
'select_all_none' => true,
),
),
'type' => 'user',
);
return $meta_boxes;
}
