Cant get NavMesh

Have the same problem as here: http://hub.jmonkeyengine.org/forum/topic/what-is-mylevel-in-navmesh-example-code/, but I dont understand. How am I supposed to use getGeometry for spatial. Its so unclear.

If you have a node (which is what a loaded j3o scene is), then you can call:
Geometry navMesh = (Geometry) ((Node)scene).getChild(“NavMesh”);

I have a question, and its a little out of topic(or not, you decide). So I did what you said and it worked(I tried out normens code: http://hub.jmonkeyengine.org/forum/topic/ai-plugin-now-with-navmesh-pathfinding/. But I have a problem with adding NavMesh to the scene(at least I think so, Im still unclear on the problem). This is a picture of it.