If you read the prologue it tells you that the leader of the inmates is commanding them from floor 5 in the basement. It would make zero sense for any levels to take place outside of the prison.I don't think level 4-5 is playing in the actual prison anymore, because logically only the prison cells themselves are possible as places, maby a chapel for which there could then also be a side job. Level 4-5 could be a secret dungeon or Karryn might have to do something outside. For example, a forest, village or the imperial palace.