As far as I know, there’s no approriate equivalent for CardDAV (address books). Other possible mechanisms would be a group principal membership, but that’s currently very wide-spread.
Short answer: It’s a CardDAV limitation.
Why it is not possible to select multiple contact folders?
Android only has one address book, and synchronizing multiple “contact folders” to one address book results is not a well-defined process. How should this work?
For further discussion, please follow up in issue #55.
OK that’s clear. My idea was, that DAVdroid creates e.g. 5 accounts if I select 5 contacts folders. In this way I don’t need to create and configure 5 accounts manually.
DAVdroid is awesome!!!