Use this activity to revoke all security groups from a permission set. You can perform this option by clicking the Revoke All button
on the Security Grants Filters by Permission Set page. Once you click the button, a dialog box will appear asking
for confirmation to perform this operation. You can choose either OK to proceed or Cancel to stop.
Refer
to the technical documentation for further details:
Security Groups by Permission Set
As a result of this activity, all permission sets are revoked from a security group.