Hi @Anes, just to understand your problem statement.
It is unclear to me whether the place to navigate around is fixed and known before hand (e.g. you want it for the station.babylon mesh you’ve created yourself and for that mesh only, so a fixed set of levels for example), or you want to navigate through any imported mesh by anyone not known beforehand?
If the model is fixed beforehand you could embed the navigation nodes/routes right into the model, instead of the need to dynamically generate/compute the nodes at runtime. This is actually quite a common practise.
In the image above I painted blue circles as nodes and green lines as valid routes to choose from. Red circle is the user position at the moment. User wants to move to blue circle noted ‘EXIT’. Now if the model (or set of models) you use are “fixed” (‘you made them yourself’), you could put those kind of waypoints right into your model, hide them for the user but use them as the points and routes for a standard path finding algorithm. So into the algorithm put blue circles and green routes, as starting position closest blue circle to player. Algorithm will give you the array of nodes to traverse to get to EXIT. This approach is referred to as waypoint navigation.
Another strategy sometimes used is to load a simplified model (with easy planes, less detail than original mesh) that is used for collision and compute all nodes/routes at runtime.