On order homepage, it will be useful to be able to see the sku(s) associated with each order.
Adding in the list of filters a field to search for a sku will allow the users to perform some actions on a specific set of orders. For instance, users could now export this subset of orders or easily accept/refuse all orders of a product which is out of stock.
Guest
Filtering orders by product ID seems a pretty rare use case.
when that happens to you I advise you to
1) download orders by clicking on "Exportation" link at the top right of order list
2) in column "OrderItem_MerchantImportedProductId" and/or "OrderItem_MerchantProductId" you can find ordered product ID
3) identify the order(s) matching the required product ID, save the "Order_MarketPlaceOrderId"
4) in BeezUP, orders list page, paste all your "Order_MarketPlaceOrderId" separated by "|".
This is longer than having a product filter, but it works :D