Azure Devops - master backlog and group members viewing permissions

Hi,
I'm looking for a tip on how to setup separate team backlog and boards under a single Project In Azure. Current, we have 3 backlogs which are setup based on teams/area's.

However, one of the teams backlogs/boards is presenting info from a different area/team. We need to separate the backlogs/boards for security purposes.

 

Thank you in advance!