bp_activity_screen_single_activity_permalink()

function bp_activity_screen_single_activity_permalink() {
	// No displayed user or not viewing activity component.
	if ( ! bp_is_activity_component() ) {
		return false;
	}

	$action = bp_current_action();
	if ( ! $action || ! is_numeric( $action ) ) {
		return false;
	}

	// Get the activity details.
	$activity = bp_activity_get_specific( array(
		'activity_ids' => $action,
		'show_hidden'  => true,
		'spam'         => 'ham_only',
	) );

	// 404 if activity does not exist
	if ( empty( $activity['activities'][0] ) || bp_action_variables() ) {
		bp_do_404();
		return;

	} else {
		$activity = $activity['activities'][0];
	}

	/**
	 * Check user access to the activity item.
	 *
	 * @since BuddyPress 3.0.0
	 */
	$has_access = bp_activity_user_can_read( $activity );

	// If activity author does not match displayed user, block access.
	// More info:https://buddypress.trac.wordpress.org/ticket/7048#comment:28
	if ( true === $has_access && bp_displayed_user_id() !== $activity->user_id ) {
		$has_access = false;
	}

	/**
	 * Fires before the loading of a single activity template file.
	 *
	 * @since BuddyPress 1.2.0
	 *
	 * @param BP_Activity_Activity $activity   Object representing the current activity item being displayed.
	 * @param bool                 $has_access Whether or not the current user has access to view activity.
	 */
	do_action( 'bp_activity_screen_single_activity_permalink', $activity, $has_access );

	// Access is specifically disallowed.
	if ( false === $has_access ) {
		// If not logged in, prompt for login.
		if ( ! is_user_logged_in() ) {
			bp_core_no_access();

		// Redirect away.
		} else {
			bp_core_add_message( __( 'You do not have access to this activity.', 'buddyboss' ), 'error' );
			bp_core_redirect( bp_loggedin_user_domain() );
		}
	}

	/**
	 * Filters the template to load for a single activity screen.
	 *
	 * @since BuddyPress 1.0.0
	 *
	 * @param string $template Path to the activity template to load.
	 */
	$template = apply_filters( 'bp_activity_template_profile_activity_permalink', 'members/single/activity/permalink' );

	// Load the template.
	bp_core_load_template( $template );
}