How to change the terrain layer opacity in GE Pro?

Is there a way to change the opacity of the terrain layer in google earth pro? I have a 3D model of underground features which won't show up with the terrain layer turned on because it is "above" them in space. If i could change the opacity of the terrain layer to 50% then we should be able to see through the terrain layer and see the underground 3D model. Right now to see it the terrain layer needs to be turned off and it appears to float above the earth.

Thanks 

Hi, Google Earth is not designed to locate objects underground.
It was talked about a long time ago but maybe was not approved at Google.
However, you can start a wish in the Help Forum.