Set up a Smart Group in Mountain Lion Contacts
The big advantage of a Smart Group over a regular group is that when you add a new Apple contact, that contact automatically becomes a member of the Apple Smart Group with no further action on your part. And if you delete a card or modify it so the contact no longer matches the Smart Group criteria, the contact is removed from the group automatically.
To create a Smart Group, follow these steps:
Choose File→New Smart Group or press Command+Option+N.
A Smart Group sheet appears in front of the Contacts window.
Give the Smart Group a name.
Select the appropriate items from the menus: Any, Company, Contains, Email, and so on.
In the figure, the Smart Group includes any contact that contains Apple in the Company field or @apple.com in any e-mail field.
When you’re happy with the criteria specified, click OK.
To delete a group or Smart Group from your Contacts, click to select it and choose Edit→Delete Group.