Master & Sub Opportunity link in BW

Hi gurus,

I am trying to link master and sub opportunity in BW for reporting.

CRM team suggested using doc flow :

using Function Module CRM_DOC_FLOW_READ_DB.

ROLETYPE = VORGAENGER means u2018NEXT DOCUMENTu2019

ROLETYPE = NACHFOLGER means u2018PRECEDING DOCUMENTu2019.

And OBJTYPE = u2018BUS2000111u2019 means Opportunity.

So, while reading the doc flow table we have to make sure that objtype_a and objtype_b are both u2018BUS2000111u2019.

Does anyone know if there is a standard way of linking the two in BW? I found an old SAP document that talks about special fields in the item and header extractor that gets filled.

http://help.sap.com/saphelp_bw32/helpdata/en/37/ab9a3e9aa69b01e10000000a114084/Release-Infos_e.pdf

None of these fields is currently being populated in our system.

Thanks for your help,

Nick