SAP BW and BOBJ Role syncup

/people/ingo.hilgefort/blog/2008/09/19/businessobjects-and-sap--configure-sap-authentication

As per the blog

For each role that is imported BusinessObjects Enterprise generates a user group and

By importing SAP roles into BusinessObjects Enterprise, you allow role members to log onto BusinessObjects Enterprise with their usual SAP credentials.

In SAP BW each user has 2 roles

1)Object Role

2)Data Role

So the question here is do I need to import both roles in the Business Objects enterprise and how do i sync that up with my BOBJ user group of Universe and WebI then ?

Thanks