In Receipts page, search for the Lot/Batch Number. Order Ref 1 field will be the PO Number(s) the Lot/Batch was received on.
In Inventory Transactions History page, search for the Lot/Batch Number and Order Type = Purchase Order. Order Ref 1 field will be the PO Number(s) the Lot/Batch was received on.
In Lot Batch History, search for the Lot/Batch Number. Check the Transaction Description and Order Type. Order Ref 1 field will be the PO Number(s) the Lot/Batch was received on.