bp_groups_register_group_type( string $group_type, array $args = array() )

function bp_groups_register_group_type( $group_type, $args = array() ) {
	$bp = buddypress();

	if ( isset( $bp->groups->types[ $group_type ] ) ) {
		return new WP_Error( 'bp_group_type_exists', __( 'Group type already exists.', 'buddyboss' ), $group_type );
	}

	$r = bp_parse_args( $args, array(
		'has_directory'         => false,
		'show_in_create_screen' => false,
		'show_in_list'          => null,
		'description'           => '',
		'create_screen_checked' => false,
		'labels'                => array(),
	), 'register_group_type' );

	$group_type = sanitize_key( $group_type );

	/**
	 * Filters the list of illegal group type names.
	 *
	 * - 'any' is a special pseudo-type, representing items unassociated with any group type.
	 * - 'null' is a special pseudo-type, representing users without any type.
	 * - '_none' is used internally to denote an item that should not apply to any group types.
	 *
	 * @since BuddyPress 2.6.0
	 *
	 * @param array $illegal_names Array of illegal names.
	 */
	$illegal_names = apply_filters( 'bp_group_type_illegal_names', array( 'any', 'null', '_none' ) );
	if ( in_array( $group_type, $illegal_names, true ) ) {
		return new WP_Error( 'bp_group_type_illegal_name', __( 'You may not register a group type with this name.', 'buddyboss' ), $group_type );
	}

	// Store the group type name as data in the object (not just as the array key).
	$r['name'] = $group_type;

	// Make sure the relevant labels have been filled in.
	$default_name = isset( $r['labels']['name'] ) ? $r['labels']['name'] : ucfirst( $r['name'] );
	$r['labels'] = array_merge( array(
		'name'          => $default_name,
		'singular_name' => $default_name,
	), $r['labels'] );

	// Directory slug.
	if ( ! empty( $r['has_directory'] ) ) {
		// A string value is intepreted as the directory slug.
		if ( is_string( $r['has_directory'] ) ) {
			$directory_slug = $r['has_directory'];

		// Otherwise fall back on group type.
		} else {
			$directory_slug = $group_type;
		}

		// Sanitize for use in URLs.
		$r['directory_slug'] = sanitize_title( $directory_slug );
		$r['has_directory']  = true;
	} else {
		$r['directory_slug'] = '';
		$r['has_directory']  = false;
	}

	// Type lists.
	if ( true === $r['show_in_create_screen'] && is_null( $r['show_in_list'] ) ) {
		$r['show_in_list'] = true;
	} else {
		$r['show_in_list'] = (bool) $r['show_in_list'];
	}

	$bp->groups->types[ $group_type ] = $type = (object) $r;

	/**
	 * Fires after a group type is registered.
	 *
	 * @since BuddyPress 2.6.0
	 *
	 * @param string $group_type Group type identifier.
	 * @param object $type       Group type object.
	 */
	do_action( 'bp_groups_register_group_type', $group_type, $type );

	return $type;
}