Setups and steps to enable: Add requisitions from Multiple BUs to single negotiation

Summary:

We have multiple BUs with each BU having both Procurement and Requisitioning business function enabled. Our requirement is to add multiple requisitions from different BUs into a single RFQ.

Content:

We have enabled service provider relationships but the requisitions are getting assigned to the default procurement BU(Same as Requisitioning BU) and we are not able to select them for processing through different BU.

What would be the setups and steps to add requisitions from multiple BUs into a single negotiation?

Version:

Fusion 23B