Grouping of PR into one PO by vendor and by plant

We are using SRM 5.0 connected in extended classic mode with ECC 6.0. We run MRP in ECC to create purchase requisitions (one per item/material) and we transfer them to SRM for processing. For those materials with contracts in SRM purchase orders are created automatically. The issue is that SRM creates one PO per PR and no grouping is done. We are creating multiple PO for the same vendor and we would like to group all the PR in only one PO per vendor and plant. How can we do that? Is this possible?

In ECC without SRM you can group PR with assigned source of supply using ME59N (auto PO). You can group them based on different criterias such as company, contract, plant, etc.

Thanks and regards, Jose Oyon.