Hi Ravi-
I just read your original post and was going to recommend National Accounts for this! It can basically do this rollup you are looking for.
There are two ways I can think of for grouping products. One is a combination of using the item classes and the User Category fields defined in both the item classes and each inventory item.
If you set up a User Category in an item class, you can roll that down to the all of the items that are part of the class.
In each of the inventory items, those same User Category fields can be accessed in Item Maintenance > Options button.
Through reporting or SmartList you could view/report on those User Category fields and make some kind of hierarchy.
The other way would be to set up an Extender window with lookup fields to enter the information. Then, like above, use reporting or SmartList to view the hierarchy.
I hope this helps.
Joe
