How to change AI Navigation in game

Hello everyone! I’ve implemented some simple mechanics in my game, but faced not so simple problem. Is there are any ways to change AI navigation with events in the game (for example when you hit a switch). The problem can be clearly seen on the bridge example on the screenshots below. I’ve placed bridge in the editor activated and it generated navigation, But how to get rid of it and change it, for example, with nav link I don’t know.