In v6 as you intersection would reveal and consider the number curves of another hidden layer…so hiding objects with layer on or layer hidden makes no difference.
By “hidden” do you mean:
- Objects which have been hidden using the HIde command?
- Layers which are turned off?
- Objects which are not visible because they are behind other objects?
1 & 2
As far as I can tell, this is the same behavior as it was in RH5, and is by design of the command.
(Intersecting with an object that is part of a group will intersect with the entire group, irrespective of visibility of any other objects in that group)