Snap restore is by volume or file.
To restore a directory you could clone the volume from a snapshot, and then copy the directory back from the clone.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
Independent NetApp Consultant, K&H Research http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, Unitek Education http://www.unitek.com/training/netapp/
(P.S. I appreciate points for helpful or correct answers.)