I use Wordpress 3.1 and Buddypress 1.5.3

I want to change the Activity section (or add another nav item next to it) to display the following subnav sections:
- all posts submitted by user filtered by a certain custom field
- all posts that the user added to favorites

In other words, I would like to replace the activity loop with the Wordpress content loop for displaying all the posts submitted by a certain user categorized in different subsections.

I can’t seem to find any resources about changing altogether the way Activity works or how to replace the activity stream loop with the Wordpress content loop.

I appreciate your help on this one