How do I group on second automation yaml

OK, so I know how to make two automation files…

automation: !include automation.yaml
automation 2: !include automation_harmony.yaml

And I can group an automation
name: Christmas
- automation.ChristmasLightsOnAtSunset

But how do I group something from “automation 2”?

put all of the automation.yaml & automation_harmony.yaml in the same folder. my automation is in config/automation/
configuration.yaml will be automation: !include_dir_merge_list config/automation/