Good question. Something like this isn’t possible:
show [group-1] if [group-2] is not visible
Groups are not considered as input fields, so you won’t even be able to select a group after the if. But it makes sense, so I might add this to the PRO version at some point.
For now, however, you’ll need to invert the conditions for the other group.
So if you have some conditions like this:
show [group-1] if [field-1] equals "something"
show [group-1] if [field-2] equals "something else"
You might, create an additional condition like this to make sure group-2 is only visible when group-1 is not:
show [group-2] if [field-1] not equals "something"
and if [field-2] not equals "something else"
