Openfire to see users in differnt OU's

I am stuck trying to get Openfire to read users in different OU’s in the tree. I am trying to use group mapping to read the OU’s, our structure has all users in a new OU with a name of blank USERS and in that OU has multiple OU’S for departments then the users for each department. I am trying to usegroup mapping with a group filter of (&(objectClass=organizationalPerson)(memberOf=OU=blank USERS,cn=accounting,dc=companyname,dc=net))

I am stuck, any help would be greatly appreciated.