How SRM decides confirmation transfer via RFC/IDoc?

Hi Experts,

I created single PO for both Goods and Service items in SRM ECS. I cannot confirm both PRODUCT_TYPE items (01 and 02) together in one document, can only be confirmed separately.

To create confirmation, SRM takes PO data from ECC, not from SRM (I guess its standard behavior), so I would like to know which FM separates and groups the Goods and Service items when we are inside CREATE CONFIRMATION page and we will find either Goods OR Service items?

Once confirmation is created, somewhere in the call stack starting from BBP_PD_CONF_TRANSFER, the field I_BE_OBJECT_TYPE gains value BUS2017 if its a Goods confirmation and BUS2091 for Service. According to this system creates IDoc for Goods and transfers confirmation via RFC for Service items.

Thanks!

Regards

Karthik