back-sql objectClass mapping

["Steve Tarkalson" <starkalson@invizeon.com>]

 I am using back-sql and I want my directory to contain nested OrganizationalUnit objectClass's like so:

  + ou=Groups           {OrganizationalUnit}
    + ou=G1               {OrganizationalUnit}
      + ou=G1Users     {OrganizationalUnit}
         - sn=                {Person}

Each of the OrganizationalUnit classes in this hierarchy needs to be mapped to a different table.
I am not sure how to do this given how objectClass-to-table mapping is facilitated in ldap_oc_mappings. 

Any insights would be greatly appreciated.
Thanks.