If you want to delete a users activity from the backend, you may follow the steps below:

    1. Navigate to the BuddyBoss dashboard - Activity.

    2. Click the dropdown beside the Filter, select activities, and click on the "Filter " button.

    3. Click the checkbox beside the Author and hover over the item under the Activity column to highlight the option if you want to mark it as spam or delete it permanently. 

    4. You can also use the Bulk actions filter.

Note: You may need to manually uncheck the boxes for those other users that you do not want to include.