After killing a Arisen Congregators in Sohn District you can find the passage to the elevator (which you saw after killing Celestial Beast, it was inactive) at the following location, behind the funicular.










Going up to the 3rd floor, you will see panels on which you need to enter codes to deploy the lens towers.










The lens towers allow you to open the double-ringed force fields once a day, when 2 circles meet in the clock in the upper left corner.










Door A - Sohn District place, opens after defeat Arisen Congregators, corridor (pile of corpses, small stairs, left, straight, right, straight, left) leads up to a one of four Archon Knight (achievement secret boss):
Eye 2: 2602 9417
Eye 4: 5624 7947

Door B - Sohn District place, opens after defeat Arisen Congregators, the gravity line leads up to a room full of loot:
Eye 2: 3898 9450
Eye 3: 5012 3677

Door C - Alma Mater Atrium - Cabaret bonfire:
Eye 4: 6080 7797
Eye 5: 2856 5003

Door D - Ikari Walkways - Crashed Tram bonfire:
Eye 3: 5440 3585
Eye 5: 2029 5238

How to rise Second Tower
After you have killed the Artillery Boss in Ikari Walkways (Metro bonfire, as i remember), you go to the lower part of the Arcology Underside, where the Mall area is. At the opposite end from where you start is door to Alma Mater Atrium, a circular room with a tower in the middle. You will find the tower key, then take the elevator to access the tower controls. You can then raise the tower, which simultaneously activates the eye ring and allows you to take the elevator to the top of the Alma Mater.