There are a few approaches you can use here using table calculations, data blending, custom SQL or RAWSQL.
I started putting an example together using the Tableau coffee sales data, but got distracted by this issue with the approach I was trying to use with table calculations, which means that it no longer works in version 7.0.
So for now I've just attached a workbook with your sample data showing how to do it with a simple custom SQL connection to get the latest dates and then data blending to find the associated stock on hand. I'm fairly sure it would still be possible with a different approach with table calculations, but I ran out of energy. There are lots of other ways to do it, I'm sure.
Latest Inventory.twbx.zip 52.0 KB