Ok, I found the solution: you have to capture  witha function and traverse the whole tree recursively


On Sun, 18 Aug 2024, 7:24 pm Eli Zaretskii, <eliz@gnu.org> wrote:
> From: Pranshu Sharma <pranshusharma198@gmail.com>
> Date: Sun, 18 Aug 2024 14:57:10 +1000
>
> I am trying to write a major mode in which all instances of a node in another matched node. For this, recursion
> is needed, and for that it is necessary to store a match in a variable:
> Say I want to highlight all instances of (x) that are inside y in the following parse tree, where bolded means I
> want to match:
> (x) in (q (y (x) (l (x) (l (x) (p))) (x))
>
> "(y) @test
>         @test . (_) @font-lock-variable-name-face"
> "(y) @test
>         (@test . (_) @font-lock-variable-name-face)"
> "(y) @test
>         (test . (_) @font-lock-variable-name-face)"
>
> All of the above fail, which leads me to think that @test stores the text instead of the tree. In this case, how
> would I recursively match all instances of

Adding Yuan.