Buddypress for wordpress Main Activity filtering AJAX

I am trying to wrap my head around how these are all connected. I am trying to add some functionality to my main activity AJAX query if a button is clicked. I see the _inc/ajax.php to edit and have looked through it, but not sure where to edit it to include new options or new loops.

As of now it seems I can find some of the features listed but I am getting stuck on how they get connected up specifically when creating my own new custom loops to be used. I created a update-loop.php and put this in my theme folder in a new directory called ‘update’ but can’t seem to get it loaded up correctly.

All I want is to get the filtering option to filter new blog posts. (if possible new blog posts from a specific category, which looking through the available options and don’t see it anywhere). Note I am NOT using wordpress Mu.

Thanks for any help or guidance, I have asked on the buddypress support forums (lost cause) but I never get any feedback or any peep out of any one there.

———EDITED:

Let me clearly ask at least one question that would be very helpful in my knowledge and future development with buddypress in working using AJAX.

How can I/If possible create my own custom loops and use them within the ajax filtering options on the main activity wall?

Please any help would be greatly appreciated…