Hierarchies in SAP

Hello - this is a strange question, but does anyone know of a resource online where I can find a list of all the hierarchies in SAP by module. For example SD has the customer hierarchy, MM has the product hierarchy, and FI has the standard ledger hierarchy.

It would also be helpful to know how these hierarchies are used from a business process perspective. For example, the customer hierarchy can be used for pricing and discounts, etc.