twig_tweak-8.x-2.8/tests/twig_tweak_test/twig_tweak_test.links.menu.yml

twig_tweak.link_1:
  title: Link 1
  menu_name: twig-tweak-test
  route_name: <front>
  expanded: true
twig_tweak.link_2:
  title: Link 2
  menu_name: twig-tweak-test
  route_name: <front>
  parent: twig_tweak.link_1
  expanded: true
twig_tweak.link_3:
  title: Link 3
  menu_name: twig-tweak-test
  route_name: <front>
  parent: twig_tweak.link_2