I modified the default menu.html partial sample code from the hugo docs to use the tailwindcss group-hover syntax. I made the children menu inside a container div so it is a sibling to the main anchor and on hover it appears. Still needs style work.

I use front matter to create the simple menu here.

+++
[menu]
 [menu.main]
  identifier = 'peaceful'
  weight = 22
+++

Then a child menu of that would use that identifier. On a page that will be in the main menu sub-nav. This system is not well suited to go beyond 1 level of depth, it works but becomes very unweildy in the actual nav.

[menu]
 [menu.main]
  parent = 'peaceful'
  weight = 22
  name = 'random peace'