Dropdown menu in registration page with BP xProfile

I am following up on a closed topic in which another user was requesting a drop-down menu for group selection (i.e., as opposed to the default checkboxes). My site will only allow each member to join one group upon registration, so I do not require the multiple group selection functionality offered by checkboxes.

Alternatively, I can use the default checkboxes if I can limit the number of boxes a user can check (as per this other closed topic).

Any feedback is definitely appreciated.

https://wordpress.org/plugins/buddypress-registration-groups-1/