This support article discusses how to locate the Lot, Lot 2 and Serial number data when editing a Fulfillment.
Drill down into the Sales Order screen and select Fulfillments.
Click on the Active Fulfillment you want to edit the Batch for.
Select the Preferred Batch drop down menu to view the active Batches (Lots) you have in the database for that SKU for that warehouse location. As you select the different Batches from the dropdown menu, it will lookup the Lot 2 and Serial Values for you.