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You can control who can access a file by setting permissions at the Group level. This makes it easy to manage access for multiple people at once.
Go to Groups.

You will see three built-in Group types:
Group Owners – full control (manage access and edit content)
Group Members – can edit content
Group Visitors – view-only access
Click on any Group (Owners, Members, or Visitors).

Edit the permissions for that Group as needed.

Important:
Any permission you set at the Group level applies to everyone who belongs to that Group. You do not need to update each person individually.