I shared the directory where most of our Unix-Homes are located under the CIFS sharename UNIX_HOMES. There's no problem to connect \filer\unix_homes, but I cannot connect directly to a sub-directory, i.e. \filer\unix_homes\alex.
As has already been stated, the cifs.home_dir option of Data ONTAP might provide you with the functionality that you are looking for.
However... I suspect that you *might* be under the impression that CIFS shares are supposed to work like NFS exports in the above respect. Alas they don't.
As you probably know, if you export "/home/keith" via NFS, it makes it possible to directly mount any subdirectory of "/home/keith" from an NFS client (e.g. "/home/keith/docs/cifs" or somesuch). Shares aren't like that. If you share "/home/keith" as "KEITHDIR", all that you can connect to from a CIFS client is "\FILERNAME\KEITHDIR". You can't do something like a:
net use q: \FILERNAME\KEITHDIR\docs\cifs
Keith