Chief works with material layers when importing, so when you make something to import you need to apply materials for where you want chief to see them before you export.
I'm not familiar with SolidWorks workflow but in 3ds max I need to make a specific material for the cab, countertop, hardware, etc. I then need to apply the materials to the correct locations on the model then export/import should show the material layers in Chief.
I'll dig into SolidWorks tomorrow morning if this is still kinda confusing and help out more. Also, if you post your model I can show you how I do it in 3ds Max if that helps at all.
CADustin's post in Importing Created Content Not Showing Materials was marked as the answer