Curently member permissions are very powerful at board level. I really cannot complain here, one does have excellent control over who can do what.
It would be even more powerful if membership permissions can be restricted down to folder level. That would provide an incredible level of control and allow even more powerful views when using the Overview mode in parent folders.
Would love to see this. That would really be a huge addition.
Hi @birgli, thank you for suggesting this.
The community and the Infinity team have identified the necessity of having those permissions’ settings at the folder level. We have this in our backlog, but also we invite you to vote on it if you haven’t already.
For now, the main idea is to allow access to your team members only on certain folders, but we will also think about adding folder-level permissions as well.
Have a nice day! 
Hi Jovana, Thanks for the response.
Access only to certain folders is basically what I was suggesting
this with essentially the same granularity you provide at board level.
Sounds like a long backlog list!