lower level display in grey

[Stefano_68]

Good evening to all,
I'm working on a multi-storey building
in drawing a level I would like to see the lower level (already drawn) in grey and unchangeable.
I tried by increasing the viewing range, but the lower level appears to me selectable and white.
Thank you and good evening!

 

[Tristan]

you must enable the view below (or range below above 2016 r2) from the properties of the current view and disable in the bottom right the selection of the elements belowhttp://help.autodesk.com/view/rvt/2016/ita/?guid=guid-8bebcef0-ce2c-4635-8c7c-9d03503c0b79