esphome/tests/unit_tests/fixtures/substitutions/08-include_hierarchy.input.yaml

substitutions:
  a: 10
  b: 20
  x: 79

test_list:
  - !include
    file: level1_package.yaml
    vars:
      x: ${x+1}
      y: ${d*2}
      c: ${a}
      d: ${b}
  - a: ${a}
    b: ${b}
    x: ${x}