How to edit the single post loop

I’m confused, I’m trying to edit the single post loop for buddypress daily so I go to the buddypress-postloop.php file but it don’t work. After looking at the single.php file I noticed there is no call to this file at all. Instead it calls this <?php bp_wpmu_singleloop(); ?> How do I edit that? I’ve worked with a previous version of daily but it was set up different, like it called that file. Thanks