Configuring the Group Assignment Override field

Create a checkbox field on the object to which you want to apply the override. It can be called Group Assignment Override. The default value is unchecked.
Grant Read/Edit permissions to internal profiles as needed.
Navigate to Group Assignment Builder.
Create a new group called "Override" (or any other example you want to give where it would indicate an override.)
Ensure this group is ordered to be the first of its object type. For example, if you have three contact groups, ensure the Override group is ranked number 1.
Criteria is Group Assignment Override = True.
Do not add any members to the list.
Save.
Regenerate the corresponding object trigger.
Repeat steps for any additional objects where override logic should be applied.