Google said you can now manage reviews in bulk for multiple listings. Google wrote "businesses can view reviews for multiple listings at once. With bulk reviews, you’ll be able to view, reply to, and flag reviews for multiple listings from one place."

Just a heads up that this feature is available in all location groups with 500 or fewer locations. It is currently not available for organization accounts.

You should be able to access this yourself by going to business.google.com/reviews. Or logging into Google My Business and clicking on "manage reviews" on the left side. Here is a screen shot:

Forum discussion at Twitter.