Alexa Smart Home Groups. Initially this makes most sense when talking about smart lights like those from philips hue and lifx. First create a group to house the echo devices you want to include in the multi room playback.
A smart home group allows you to control several devices at once by speaking to alexa. To create a smart home device groups in the alexa app. Select plus and then add group.
Select the devices you want to include and then select save.
Select plus and then add group. Open the alexa app and tap the devices icon at the bottom right of the screen. Initially this makes most sense when talking about smart lights like those from philips hue and lifx. First create a group to house the echo devices you want to include in the multi room playback.