Well that is the level you last recorded on your play through videos. Level 4 The Ruins I can tell because of the purple squares on the map that is the pillars with the mini gun and tek armor on top of them.
Level 7's broken into a bunch of pieces, and pretty linear, so I took some screenshots leading up to them rather than the map.For the second key, you need to press that button in the second shot, then go through a passage that opens up back in the direction of the entrance,https://imgur.com/a/9vvBV