Ranger: Group/User Permission import

I have perfectly working Ranger setup synchronized with LDAP/AD and using HDFS repository. I would like to import all existing groups/users permissions as ‘Policy’ in Ranger UI, so that there is not need to create new policies. I already have several groups having different permissions on HDFS resource path. Creating new policies for each group would be very-very tedious task for a cluster having petabytes of data, 400+ nodes, and 100+ groups.