Ok, this has really bothered me. Selecting an addressbook

[Harley77]

In Zimbra, you have the ability to create multiple address books to organize and separate addresses, however, when composing a message and clicking To:, you can't select any of them. You have to view a combined list or the GAL. Totally useless. Is there some technical reason this has never been implemented?

[macdevin]

Our users have complained about the same issue.
I've yet to look to see if this is in bugzilla yet.

[mmorse]

Bug 32718 - RFE: Contact picker should allow selection of individual addressbook folders

You can also select type 'contacts' on the right and start the search off by in:folder. But only if you know the name exactly - no autocomplete there yet like the the main search bar has.