In a browser (or app classic view)
To duplicate a Buzz, open the settings menu  and choose ‘Duplicate’  . You’ll get the option to give your Buzz copy a new title, and can choose to keep all the existing participants.
Note that comments in the original Buzz are not copied to the new one.
In the app
Click the Buzz options button (the 3 dots at top right), and select the 'Duplicate' button on the Options screen.