Previously you needed to combine two commands by "and". Today, Google announced on Twitter that support for up to three simultaneous commands is rolling out to users in the U.S., U.K., Canada, and Australia.
First up, Google tweeted that Google Home now understands up to three queries together, though it says the feature is only available in English in the US, UK, Canada, and Australia. To this end, Google Home can now respond to strings of up to three commands at once.More news: Griezmann: Today isn't the day to discuss my future
Additionally, as noted by Android Police, it would appear that the Multiple Actions feature is live, too.
Back at Google I/O (Google's annual developer conference), the company had announced that it was working to improve support for multiple commands like these and make them smarter. For instance, you will be able to say, "Ok Google, switch on the lights and play music and turn up the volume", all in one go, and Google Assistant will do all that for you. If you want Google to perform a more complicated action, make sure to send it to your device from the Google Assistant website. For example, "turn on the lights in the living room and turn on the lights in the kitchen".
To check if you're on the latest firmware version, use the Google Home app on your phone and check the device info for your Google Home device.