When a configuration is used it is generally bound to the bundle of the configuration consumer. The intent originally was that configurations can only be consumed by a single bundle (actually a single consumer such as a ManagedService registered with the configuration's service.pid).
As of recent Configuration Admin specifications the configuration binding has been defined more openly such that configurations can be shared amongst consumers in different bundles.
The web console currently only displays the bound location and allows for clearing the binding (setting it to null). To fully support the new configuration location regions, GUI should be provided to change or set the location to some explicit string, such as "?*" to not restrict the configurations use at all.
Also, the web console should be extended to by default set a configuration location. For backwards compatibility it would probably make sense to have such functionality configurable, since Configuration Admin implementations not supporting the location regions would fail using configurations bound to locations such as "?*".