bb_global_search_default_items_to_search( mixed $value )

function bb_global_search_default_items_to_search( $value ) {
	if ( empty( $value ) ) {
		/**
		 * Setting > what to search?
		 * If admin has not selected anything yet( right after activating the plugin maybe),
		 * lets make sure search results do return someting at least.
		 * So, by default, we'll search though blog posts and members.
		 */
		$value = array( 'posts', 'pages', 'members' );
	}

	/*
	 * If member search is turned on, but none of wp_user table fields or xprofile fields are selected,
	 * we'll force username and nicename fields
	 */
	if ( in_array( 'members', $value ) ) {
		// Is any wp_user table colum or xprofile field selected?
		$field_selected = false;
		foreach ( $value as $item_to_search ) {
			if ( strpos( $item_to_search, 'member_field_' ) === 0 || strpos( $item_to_search, 'xprofile_field_' ) === 0 ) {
				$field_selected = true;
				break;
			}
		}

		//if not, lets add username and nicename to default items to search
		if ( ! $field_selected ) {
			$value[] = 'member_field_user_login';
			$value[] = 'member_field_user_nicename';
		}
	}

	return $value;
}