The video was captured during an Impossible difficulty playthrough.
The final boss fight is broken up into 4 phases. In the first phase, shoot the weak points around its mouth while avoiding its tentacles and the pods it spits out. In the second phase, clear out all the necromorphs and collect ammo/items as needed.
During the third phase, shoot the weak points inside its belly when they are exposed. Between exposures, the hive mind will spit trails of acid down the area (only 1 active at a time). Bait it into spitting on one of the sides to give yourself more room. During the 3rd and 4th wave of acid trails, the Hive Mind will spit acid 3x each. It will also slam down its tentacles 4x where you are standing, so plan to run from one side of the safe area to the other (back corner to middle-side works best).
In the final phase, shoot the weak point in the Hive Mind's mouth as you are hanging from its tentacle. It will be difficult to hit while it moves, but it will slow down and move in near the end.