https://www.techradar.com/news/google-assistant-to-get-custom-routines-for-full-smart-home-control

Google may be set to open up even more control of smart home commands to users of its Google Assistant helper.

Code found in the latest beta release of the Google app suggests that custom Routines (the smart home instruction tool kits that let a single command trigger multiple device functions) could be soon rolling out to the system as a whole.