Hi Klaatu,
Thanks for posting. I understand that you need to control your Chromecast with your Nest Hub. Great news! You can use your voice to play audio on any speaker or TV with Chromecast or Chromecast Audio, or Chromecast built-in.
You can check the article: "Play audio on Chromecast-enabled speakers & TVs with your Google speaker or display" to know how to link your devices.
Please let me know if you have any questions during the process.
Best regards,
Jenny
