It would be extremely helpful if, within a more open collection, there was the ability to restrict specific cards by group. Currently at creation, we can restrict to certain individuals, but having this expanded to include group permission ability would be invaluable. 

We want to avoid having to create private collections for teams within other teams for a handful of cards that need to be locked, when the rest of their content is open. This is resulting in having to further silo our team content instead of having a One-Stop Shop collection for them, including their more restricted cards. 

Locking each card by individual is not scalable when the team is constantly fluctuating. Each time the team shifts, we have to go back into each card and change the individuals that can access. 

Alternatively, being able to create private boards within a more public collection would solve this need as well.