function bp_activity_post_type_get_tracking_arg( $activity_type, $arg = '' ) {
	if ( empty( $activity_type ) || empty( $arg ) ) {
		return false;
	}

	$bp = buddypress();

	// Set the activity track global if not set yet.
	if ( empty( $bp->activity->track ) ) {
		$bp->activity->track = bp_activity_get_post_types_tracking_args();
	}

	if ( isset( $bp->activity->track[ $activity_type ]->{$arg} ) ) {
		return $bp->activity->track[ $activity_type ]->{$arg};
	} else {
		return false;
	}
}