bp_get_mentioned_user_display_name( int|string|bool $user_id_or_username = false )

	function bp_get_mentioned_user_display_name( $user_id_or_username = false ) {

		// Get user display name.
		$name = bp_core_get_user_displayname( $user_id_or_username );

		// If user somehow has no name, return this really lame string.
		if ( empty( $name ) ) {
			$name = __( 'a user', 'buddyboss' );
		}

		/**
		 * Filters the mentioned user display name.
		 *
		 * @since BuddyPress 1.2.0
		 *
		 * @param string     $name                Display name for the mentioned user.
		 * @param int|string $user_id_or_username User ID or username use for query.
		 */
		return apply_filters( 'bp_get_mentioned_user_display_name', $name, $user_id_or_username );
	}