that's actually still not entirely clear, I'm sorry.
On Linux each user account has a home directory associated with it. This is usually »/home/username«, e.g. »/home/janesmith« for a user called »janesmith«. You can change this folder in the UDM (Univention Directory Manager) by opening a user, selecting »Account« on the left and changing the »Unix home directory« unter the »POSIX (Linux/UNIX)« heading.
This Linux/UNIX home directory is also the folder that a user sees when she opens the user's folder on the server in the Windows network neighborhood, e.g. »\servername\janesmith« for a user »janesmith«.
Now in a pure Windows installation joined into the domain that folder has no special meaning as Windows doesn't auto-connect to it by default. You can, however, use various methods to map such a folder: logon scripts, group policies or the UDM's settings »Windows home drive« and »Windows home path« on the same »Account« tab where you found the »UNIX home directory« setting. If you use e.g. H: as the »Windows home drive« and »\servername\username« as the »Windows home path« then you should be set.
If you do NOT want to change the »UNIX home directory« but you DO want a drive on Windows be mapped to a different folder then create a new share in the UDM, create folders for each user in that share and use »\servername\name-of-new-share\username« as the »Windows home path« property in the user's account settings.
Note that you have to set both the »Windows home drive« and »Windows home path« properties for each user. In earlier Samba versions you could define those globally, but that doesn't work in an Active Directory style domain anymore.