it is quite common to have different ou for groups (containing posixGroup) and people (containing posixUser), currently it seems the config does not allow for that:
# Distinguished name of the sub tree containing Posix users and groups (mandatory) ldap_search_base_dn = ou=people,dc=example,dc=com
would be good to be able to specify separate sub trees for people and groups, without that option I can't get ldap to work for my config (wheel group for admins is in Groups ou, users to monitor are in people ou).