Alright so the two things that come to my mind are:
→ either you will have to set that path for them yourself meaning the ai will just follow the path you created. search AI Patrol or something on youtube and you will find some tutorials on this.
→ or create invisible non-collision boxes which affect ai navigation (i am not sure if this will work but i think actors have a option which you can change so that they will affect ai meaning you might be able to make them avoid this).