Can anyone tell me if there is an app or other method to create a collection that only shows inventory from designated locations. For example, if I have a product that is in stock in store B, but out of stock in store A, I do not want it to be in the collection for store A (or to have it show up as out of stock in store A).
You would need to have a couple of batch services running in the background checking your inventory levels and then removing tags from products so they get removed from collections. I am assuming you automatic collections setup for this process.
If you have multiple inventory locations in Shopify then the item will still be available to purchase even though it is not in a particular collection.