Navmesh - lower priority of moving to a certain area

Hi,

I have set up a navmesh and created a character that randomly moves in it (random location service in a BT). Now I’d like to manipulate the priority of CPU generating coordinates for the character to move to for a certain area.

An example:
I have a navmesh encapsulating a city. The AI character can randomly navigate in it. It then collides with a building, so I want it somehow manipulate the navmesh during runtime (exclude current coords from navmesh?), so it won’t repeat its mistake next time.

Thanks!