Auto Action Usergroup set by Moderator?

I've created a field which consists of a dropdown list of usergroups. The field is only visible to moderators. The field is named cb_setrank.

What settings specifically would I need for a mod to pick a group from the list, and have it replace their current group with the new one?

I've tried many permutations. What I left off with is the following:

Trigger - OnAfterEditATab
Access - Everybody
Conditional - cb_setrank Equal To Recruit
Mode - Replace Usergroups
Groups - Recruits

Change trigger to after profile update. Then change your conditional to [cb_setrank]. It should work fine then. Simply edit a user, change the field, save their profile, and it should replace their usergroups.

After making the changes, nothing seems to happen.

Oh my God. Nevermind. I never published Auto Actions....

I don't suppose you know what settings I'd use to update the user's kunena forum rank as well?

I know I need to change the rank value in the kunena_users table. But I don't know the code to use to achieve it.

Typically the rank is calculated from post count, but believe you can specify an override by updating the users row in _kunena_users and adjusting the "rank" column as needed. You'll probably need to specify the rank id as seen in _kunena_ranks.