BuddyPress.org

Codex.buddypress.org is only as good as the amount of people who bother to contribute to the documentation. Failing that, reading the code (if you can read code) is always a good way.

The only parameter that bp_group_list_admins() takes is an optional group object; it defaults to the current group object from the bp_groups templatetag loop. You’d need to duplicate (and rename) this function into your plugin / your theme’s functions.php to do what you want to do with it.