Hi,

In the case of the location under the configuration menu, that is not related to the product and stocks, there is only an action added to connect those records( action name - location_open_putaway, you can refer to the button action)
the Current Stock smart button is used to connect the stock location details, it is only added using the smart button action function.

if you need to add a connection between them you need to add some relational field like a many2one or any other relational field.

Hope it helps