Right now it is not automatic. Open the Address Book, and select the personal address book you want to synchronize. Click File, Synchronize, and click Current Book.
Personal groups work great for contact lists.
You can include users from the same address book, different address books, or the Internet. The only requirement is that each person in the group has an e-mail address. And let's not limit ourselves to people. You can also include resources and other groups within personal groups. And it's so simple.