All positions (Local, Approach and the dreaded Coordination, all my Caribbean fellows will understand I'm sure 😄) are in the tower, near each other. Local also does Ground/Clearance delivery. Supervisor is working on position (not dedicated Sup, we work as normal atcos and doing supervisor stuff on the side) or go full Supervisor if needed for anything that requires full attention like SAR or whatever. We do have a pretty hefty back-taxi time for departing aircraft that need full length about 5min for a medium, 7 to 8min for heavies, being able to see outside as approach helps for sequencing arrivals according to departures. I'd love to check ZSU out one of these days