N-step approval for SO and PO

Hi all:

I'd like to implement N-step approval workflow for SO and PO in R/3, Could you please tell me if there is sap standard workflow like WS14000145 in SRM.

and are there any badi just like BBP_WFL_APPROV_BADI~GET_REMAING_APPROVERS in SRM, can be used to implement getting the approvers ?

Thank you very much !