On the Buddypress activity page, you can filter by All Members, Favorites, Mentions, ect…

How do I add a filter to only show updates from a specific user id?

There is for the "All Member" filter html below. How can I change that to a specific user id/ and the js needed?

<li id="activity-all"><a href="<?php bp_activity_directory_permalink(); ?>"><?php printf( __( 'All Members %s', 'youzer' ), '<span>' . bp_get_total_member_count() . '</span>' ); ?></a></li>