In Stellar Blade, Sector A07 is part of Altess Levoire, the underground facility you explore during the story mission of the same name. Once you reach Sector A07, you'll be presented with a floor tile puzzle, which you'll need to solve to progress.
Sector A07 Pattern Puzzle Guide (Altess Levoire) – Stellar Blade
To get to the other side of the room, you’ll need to navigate a sort of mini-maze made up of floor tiles, each bearing one of four iconic PlayStation button symbols: Triangle, Circle, X, and Square. Below you is a bottomless void into oblivion, and if you step on the wrong tile, it’ll follow you into the void. So you’ll need to be very careful. Luckily, there’s a pattern here, and if you follow it, you’ll make it through safely. And then you can continue the story of Stellar Blade and collect the second Hyper Cell.
For the first four tiles, you can only walk straight ahead, and the order of the tiles you walk on at the beginning is the order you have to repeat all the way through. So, the first four are Triangle, Circle, X, and Square, and you have to continue in the same order. It’s like starting at the top button on your controller and walking clockwise. Here’s a step-by-step walkthrough:
The first Triangle is right in front of the Square, and the Circle is right in front of the Triangle. Next, you need an X, so go to the right. And then the Square is right in front of you.