Selection Through Transparency
You can select opaque objects through transparent objects.
This includes opaque components through transparent components in an assembly as well as interior faces, edges, and vertices through transparent faces in a part.
To enable selection through transparency, click Enable selection through transparency.
and click As you move the pointer over opaque geometry that is behind transparent geometry, the opaque faces, edges, and vertices highlight. Click to select the highlighted geometry in the graphics area.
For purposes of selection, transparent means more than 10% transparent. Entities less than 10% transparent are considered opaque.
To select geometry on a transparent entity with an opaque object behind it, press Shift when selecting.
If the entire model is opaque or transparent, right-click and choose Select Other.