BuddyPress.org

I believe the correct way to do this is simply to go into the template file and rearrange the order of the <select> options so that ‘Alphabetical’ is first. ajax.php has functions that allow this to work.

for my-groups, the correct template is bp-themes/bp-default/members/single/groups.php

for the groups directory, bp-themes/bp-default/groups/index.php