The inspector in the SketchUp plugin in render mode aware. In the past when you were in render by construction and selected a construction you would see the construction object (and material layers) in the inspector. But this didn't allow modelers to change the construction assigned to a surface. Now it shows the surface object where you can see and change what construction is used.
 You have a few options.
  - You can use the info tool (black arrow with cube by it) to inspect the layers in the construction by material name.
  - You can use the inspector and manually go to the construction or material you wan to inspect.
  - You can use the construction tab of the stand alone OpenStudio application
  
 Screenshot below shows option 1.
 