A simple way to point to sub-folders in libraries is to use the old environment variables,
accessible through Control Panel -> System -> Advanced tab -> Environment Variables.
To add an environment variable inside the User or System/All section, click the New button
and define for example a variable named MUSIC
having the value C:\Users\Public\Music
,
then click OK twice.
With this environment variable,
a file whose address is C:\Users\Public\Music\Sample Music\Kalimba.mp3
can be
referred to as %MUSIC%\Sample Music\Kalimba.mp3
.
If in the future you move your music to another folder, you only need to change
the MUSIC environment variable, but all your shortcuts will still stay valid.
To find the path of any sub-folder in Libraries, open Explorer and navigate inside
that sub-folder, then click in the Location field to the right of any displayed
value (in a blank spot), and the value in the Location field will then change to
show this sub-folder's full path, that you can copy and paste.