Hi Padriag,
You can enahance the search and include a logic if all the values are blank in the search, the system should automatically add the users Org unit in the search criteria and display the result with the assigned values.
Check this threads
http://scn.sap.com/docs/DOC-39532
http://scn.sap.com/docs/DOC-5357
Regards,
karthik J