Sales report using customer hierarchy nodes

Hello SD Gurus,

I have requirement where in the client has three individual customers grouped under one category. He wants to have the reporting to be done at the category level i.e.,

For exapmle : Three power stations(NTPC) are there in Ramagundam, Hyderbad, and Vijaywada. CLient wants to have the reporting to be done at the NTPC level not at the individual entity level.

Need ur help in implementing the same using the Customer Hierarchy.

Thanks and Regards

Brahm