Can multiple WordPress sites share same document folder?

Hi.

I have a test subdomain and planning on creating a production version soon. Since both sites are essentially the same in content and configuration I am wondering if it’s possible to create a folder outside of the WordPress installation folder which File Away can see and refer to? Thus I won’t need 2 copies of the same files and both sites will see any new files immediately.

In the plugin’s control panel I can only see the installation folder, not a folder further up in the domain’s root directory.