You can find any tool by the Menu Structure HERE: https://turbocaddoc.atlassian.net/wiki/display/TC20UG/Menu+Structure

You can find the menu location of any tool by name HERE: https://turbocaddoc.atlassian.net/wiki/display/TC20UG/Tools+Mapped+to+Menus

3D Intersect


Creates one 3D object that is the overlap (intersection) between two objects.
Select two objects that overlap. Selection order is important, because the new object will have all the properties of the first object selected, including layer, and material.

Local menu option: 

Keep Original: When this option is selected the original objects used in the intersection will be retained.