HITMAN 3 and all of the shortcuts present in ON TOP OF THE WORLD mission in Dubai. There are a total of four shortcuts you might unlock during the playthrough – three of them are really close to each other (in the Penthouse and Helipad areas), while the last one leads to Atrium and main elevators. The best disguise is so far to get one of the guards in the Atrium + a keycard to the Penthouse. With these + a crowbar (you can find one for example near the Art Gallery), you will be able to open all of these shortcuts (three of them are ladders). Once you unlock any of the shortcut, you can use them later without a need to unlock them anymore. For example when you start in the Atrium Lobby, you can run straight away through the Atrium Lobby Door.
Challenges Unlocked:
Shortcut – Penthouse Terrace Ladder
Shortcut – Ventilation Area Ladder
Shortcut – Atrium Lobby Door
Shortcut – Helipad Ladder
Source