Show, Hide, Set Transparency for B-Rep Geometry and Mixed Representation
You can show, hide, or set the transparency for boundary representation geometry and mixed representation.
In the View tab, in the Show section, click the 
Geometry Display Filters list. The following options are available:
Geometry Display Filters list. The following options are available:• Boundary (B-rep)—The default transparency setting is 0%. B-rep geometry includes solid bodies and quilts.
• Mixed—The default transparency setting is 0%. Mixed representation geometry includes the geometry that is not b-rep, like facet, simplified, and volumetric geometry.
To control the transparency, move the slider. You can set the transparency only for default the appearance.
To show or hide, clear or select the check box. You can hide or show irrespective of the default appearance set for the model.