A. Create a Google Group that has the two auditors as members, and then create a Drive DLP Rule that is assigned to that Group.

B. Create two Drive Audit Alerts, one for each user, where the Visibility is "Shared Externally," and email them to the Director.

C. Create a Content Compliance rule that looks for outbound share notifications from those two users, and Bcc the Director on those emails.

D. Check the Admin Console Dashboard Insights page periodically for external shares, and notify the Director of any changes.