From your iphone or android device open the google home app.
Chromecast built in スピーカー. Chromecast built in 搭載のテレビ オーディオ. Chromecast built in speakers let you instantly stream your favorite music radio or podcasts from your mobile device to your speakers. Go to the devices tab tap the device card menu and select create group. Create a name for the group select speakers to include.
Source : pinterest.com