I have a main file containing my site model ('file A') then separate files for my building models (files B, C, D, etc).   I bring the building models into my site model file as referenced design layer viewports.   I can edit the class + layer visibilities of the DLVPs on the design layer (in site model file A) but can't see a way of showing different combinations of visibilities in viewports on sheet layers.   For example in file B I've modelled the as-existing stru