Multilevel Categorization Schema

Hi Gurus,

I am trying to create a report which shows category level 1, category level 2, category level 3. I found last hierarchy level data in table CRMD_SRV_SUBJECT. But i need to get data from category level 1 to the last category level. Heard that we need to retrieve data through UI classes. I didnt find any such classes in my search. Would be thankful if i get solution on this.

Regards

Ethan