Manage Permissions in Permission Set Groups with a Muting Permission Set (Generally Available)
A muting permission set is a handy way to increase security and ensure that only components that are required by your organization and users are accessible and, conversely, those components that shouldn’t be accessed are not available. When used along with permissions, a muting permission set gives you granular control over permissions and helps make sure you're complying with the principle of least privilege.
Where: This change applies to Salesforce Classic (not available in all orgs), Lightning Experience. Enterprise, Performance, Unlimited, and Developer editions.
Why: Suppose that your Sales Staff Users permission group contains three permission sets. And one of those three permission sets contains a Delete permission that you no longer want all group members to have. To complicate things, you also have a Managers permission set group that references the Sales Staff Users permission set. What can you do to implement this permission restriction? Instead of creating another permission set, you can use a muting permission set to constrain the Delete permission. The muting permission set contains the Delete permission that you want to disable. When you add the muting permission set to the Sales Staff Users group, those members no longer have the delete permission, but the Managers members do.