Addon nested /group configuration translation

Development
1

Thanks to @cr7pt0gr4ph7 for the nested configuration for addon available in release 2025.10. How translations are working for nested configuration ?
Example of schema:

schema:
  group:
    option1: str?
    option2: str?

In en.yaml, how to change the name of option1 or option2 ?
I tried 2 options but none are working:

configuration:
  group:
    name: Name of group
    option1:
      name: Name of option 1
    option2:
      name: Name of option 2

and

configuration:
  group:
    name: Name of group
  group.option1:
    name: Name of option 1
  group.option2:
    name: Name of option2
2

I also tried:

configuration:
  group:
    name: Name of group
  option1: 
    name: Name of option1
  option2:
    name: Name of option2
3

I answer to myself:
This is documented and need to use fields key for the subfields.