I could but this is not what I need
Imagine you have a 5 levels building and you want to show the 3rd level in isometric view without having to cut the building to slices - which is possible but takes a lot of time to do (which is exactly what I have done in this case...!).
In Revit , for example - there is a way to show the modeler only what is enclosed within a user defined box so you may work easily on this area and later - reveal the rest.