Is there any way to nest groups hierarchically in Apple Contacts?
The only possible "solution" I have (which isn't really a solution but it's what I will do if nothing better is suggested), is:


Take everyone I don't routinely contact, export their vCards individually (not in batches) (this is so that quicklook will work), and delete them from Address Book (a.k.a. Contacts).
Use Contacts for my every day common contacts, and use either a directory structure and Quick Look, or some third party app, to organize all the rest of my contacts.


This compromise preserves integration with Afred and Mail.app for common contacts, and allows me to better organize unusual contacts.  But I'd prefer nested contact groups directly in Contacts.app.