1. Open de Google Home app. 
  2. Click on the house (Home icon) and then tap ‘Add’ (+ icon). 
  3. Select ‘Create Speaker Group’. 
  4. Select the available speakers you want to add to the group and give your new group a easy to pronounce name. 
  5. You can cast music using voice commands or by choosing one of the available groups with the cast icon in one of the apps you are using.  If you have named your group ‘Living Room’, for example, you could say: ‘Hey, Google, play radio 538 in the Living Room’, and this music will be played on all speakers you added to the ‘Living Room’ group.