Validation on RFx Transaction types

Hi Folks,

I have a requirement to validate RFx draft when user created a SC with SC type as RFI(Custom field on Item details).

Requirement: For an approved shopping cart, when we create RFx draft and providing Transaction type, validation should occur. PFA.

To achieve this, I have used DOC_CHECK_BADI filter type as BUS2200, so how can I get the shoopping cart item details to validate with the RFx transaction types .

Thanks in advance.