How to make a single location visible in Default Ship-to Location while creating a purchase order?

Summary:

Our client has a thousands of locations available in the system. These locations will be attached to thousands of inventory organizations with 1 to 1 relationship. But a user from store A should be able to see only the location of Store A in the "Default Ship-to Location" field, while creating a Purchase Order. If the user selects any other location by mistake, that PO will be created against some different inventory organization. To avoid this, we want to make sure that a single, correct location is made visible for selection during PO creation. If there's a way to default