bp_search_helpers_cpts( array $helpers )

function bp_search_helpers_cpts( $helpers ) {

	$post_types          = get_post_types( [ 'public' => true ] );
	$custom_handler_cpts = [ 'post', 'forum', 'topic', 'reply' ];

	foreach ( $post_types as $post_type ) {
		//if name starts with cpt-
		if ( ! in_array( $post_type, $custom_handler_cpts ) && bp_is_search_post_type_enable( $post_type, 0 ) ) {
			$searchable_type = 'cpt-' . $post_type;
			$cpt_obj         = get_post_type_object( $post_type );
			//is cpt still valid?
			if ( $cpt_obj && ! is_wp_error( $cpt_obj ) ) {
				require_once buddypress()->plugin_dir . 'bp-search/plugins/search-cpt/class-bp-search-cpt.php';
				$helpers[ $searchable_type ]              = new BP_Search_CPT( $post_type, $searchable_type );
				BP_Search::instance()->searchable_items[] = $searchable_type;
			}
		}
	}

	return $helpers;
}