Navigating in Hangouts

Tap the Hangouts Options icon to access Snooze notifications, Invites, Archived, Blocked people, Settings, and Help & feedback.
Tap the Chatting list icon to open your Chatting list which lists all of your contacts from all of the Google Accounts that you've added.
Tap the Chats icon to open the Chats screen.

NOTE

You can also swipe horizontally to switch between your Chatting list and the Chats screen.