The main menu area when you sign in lists all the Buzzes you have access to (with the most recently active or changed ones at the top).
You can search  by title or user name (for instance to find Buzzes you have in common with a particular person). As you type the list of Buzzes will update to reflect your search term.
To open a Buzz, simply click on it . To navigate back to the main menu from a Buzz, simply click the ‘back’ button or logo at the top left in the navigation bar .