Use custom slugs in permalinks

function pm_use_custom_parent_slugs($full_custom_slug, $post) {
    global $permalink_manager_uris;

    if(!empty($post->ancestors) && $post->ancestors && is_post_type_hierarchical($post->post_type)) {
        $full_slug = $post->post_name;

        foreach($post->ancestors as $parent) {
            $parent = get_post($parent);

            if($parent && $parent->post_name) {
                $custom_slug = (!empty($permalink_manager_uris[$parent->ID])) ? basename($permalink_manager_uris[$parent->ID]) : '';
                $full_slug = (!empty($custom_slug)) ? "{$custom_slug}/$full_slug" : "{$parent->post_name}/{$full_slug}";
            }
        }
    }

    return $full_slug;
}
add_filter('permalink_manager_filter_default_post_slug', 'pm_use_custom_parent_slugs', 10, 2);