If they are in the same bin then any quantity from that bin would be suitable to confirm it during picking TO confirmation.
You need to split these quantities to 2 storage bins if you want this functionality.
If your bins are too large for a one production receipt, then you might need to reorganize your warehouse complex to make the locations(bins) smaller and optimize for your needs.
That should have been done at the first place during WM implementation...but it's never too late.