Referencing CI step

This is how we reference steps in CI step in directory in a repository

job:
  run:
    - name: specifying_a_stepn_and_directory_within_the_repository
      step:
        git:
          url: gitlab.com/josephburnett/hello-world/echo-step
          dir: sub-step
          rev: main

We would like to move to a less verbose syntax using '-' as the delimiter

job:
  run:
    - name: specifying_a_revision_and_directory_within_the_repository
      step: gitlab.com/josephburnett/hello-world/-/sub-step/echo-step@main