Third Moth Nest Break The Wall
Enter the underground section below the Outpost. You can easily find and destroy the first and then the second Moth Nest easily. Continue your journey through the underground tunnel and this will lead you to a much bigger room.
First, kill all the enemies you encounter. You will see an entrance that leads to the third Moth Nest that you need to destroy to complete the Outpost takeover. However, this entrance to the third Moth Nest is blocked by a concrete wall.