Bake Navigation Mesh inside a specific area?

Godot Version

4.2.2

Question

Hello! I got a closed map made in Trenchbroom and the NavigationRegion3D bakes a navigation mesh inside AND outside of the playing area, since I’m using the walkable areas as a method to make an enemy randomly teleport, i need these areas outside the playing area to be gone.

How can I limit the mesh baking into the area in the cyan square? (The red represents the map viewed from the player’s perspective if far away horizontally)

Many thanks to those who help.