You need to use Level.Plane like I showed in the image.
But isn’t that to “create” the planes that are going to cut? Because I copied that part of the nodes to build the geometry and it is giving that result
Yes, those are creating the cutting planes. What are you trying to get with Element.Geometry? Levels don’t have any geometry, they merely represent a plane.
oh, forget about it. my mistake. In the categories I selected “levels” instead of pipes. My bad! 
That’s because your not following @Nick_Boyts graph. Check your category
He should change category as well.
yes, It was a mistake of mine. Going to work on that later, I can only spend time on it after hours since BIM adoption here isn’t that much