How to Read Multi-level Categorization levels of a Service Request in SAP CRM

Hi All,

My requirement is to get the  Multi level Categorization TEXTS of a service request .

using CRM_ORDER_READ, we can read only the last Category details..

Can any one pls let me know how to get the Details of Category Levels : Category 1, Category 2 ....

Kindly help me at your earliest !!!

Your help is very much Valuable and timely ..

Thanks in Advance !