Membership Group:

To add the Membership Group, go to Point of Sale >> Setup >> Membership Group

Press Alt+2 to add the Membership Group. You will see the following screen fill the required fields and press Ctrl+ S to save the information

Edit The Membership group:

To edit the Membership Group, go to Point of Sale >> Setup >> Membership Group

From the list click on option icon and click on Change button. Change the desired Membership Group setup and press Ctrl+ S to save the information. You can view the added information by pressing Alt+1 to go to the list and filter the result as per the requirement.