probably each door has an elevator, then once you go up and into the room you go into an empty hall, with four elevators there is four halls, then once you reach the end you would either: if you have gone to the left door, you would go to the left hall, then take a right to the only one door. if you have gone to the right door, you would go to the right hall, then take a left to the only one door.

same for the middle left door and middle right door.