You can use the Google Drive API to access your Google drive, and you will find the files there. You can discover the location empirically, but, as it is not documented, it could change at any time. Google and others (e.g., Apple) have a habit of moving formerly-easily-visible files into obfuscated places.
To get you started, simply access your Google drive with their UI (web page or Chrome app), and you'll find the synced files. You may have to hunt around a bit with the links on the left of the Google drive web page.