Google-drive – How to find all the shared folders on Google Drive

If you know the email addresses of the people you have shared files with, all you have to do is enter the following search in Google Drive's search bar:

to: [email address]

Google Drive will then show all files shared with that user.

Google Apps does not natively support reporting on who has access to what in Google Drive. The report you are looking for is possible through a Google Apps script.

As you probably know, from the Reports section of your Google Apps admin panel, you will be able to tell how many files are externally visible.

If you are on the Google Apps Unlimited or Google Apps for Education license, you will have access to a Drive audit log, from which you may be able to generate a report based on sharing events. This could be cumbersome.

If you have a $30 to $40 USD budget, you can either procure the Drive Audit Google Sheet Add-on or the Drive Privacy script from tech blogger Amit Agarwal and produce the report.

A free option based on Stefan Lasiewski's suggestion below is to try whohasaccess.com. The app requires View and manage the files in your Google Drive permissions, among other simpler permissions.