I managed to get under the map in campaign!
How i managed to get under the map like i showed you, you have to follow these simple steps;
1; Throw a grenade (G) while the elevator is going down, after you have meet the wrong appartment.
2: Then you will get "Teleported" to this spot.
That was what ive did, and i am not sure if this is going to get patched or anything like that. I hope you guys think this is interesting, and try it out! Thanks for youre view, and also remember to comment if you have some issues. Also smash the like buttom!