How to separate the scheduler.yaml in several files?

hi everybody,
i tried to separate my scheduler.yaml in 2 oder 3 separte yaml-files.

  1. created a new folder and i copied the scheduler.yaml in.
  2. added the folder to the !include part in the configuration.yaml
  3. tested it and it worked with the scheduler.yaml in this new directory (schedules are visible in the helper part)
  4. i created a new yaml in this directory and copied one of the schedules from the scheduler.yaml in the new yaml-file
  5. changed the !include into !include_dir_merge_list
  6. checked the config and reloaded the scheduler part
  7. none of the schedules in the yaml files are visible in the helper section
  8. restart HA but the result is the same, none of the schedules is visible

So what is wrong? OR isn’t it possible to separate the scheduler.yaml file?