tree-sitter-embedded-template VS tree-sitter-comment

That may require a tree-sitter implementation for erb templated html; it may exist but if so it's less of a mainstream thing.

Some quick googling turns up https://github.com/tree-sitter/tree-sitter-embedded-template which may or may not meet your needs.

As far as I know there is currently no treesitter parser for Doxygen style comments. There is a language agnostic comment parser that is supported by nvim-treesitter that will highlight things like TODO: and NOTE: in comments. Until this recent commit nvim-treesitter provided a query for this parser that highlighted @ text in comments. It was meant to highlight a reference to a user but it doubled as a doxygen tag highlight for me for a while. I just noticed that this query has been removed and I'm not sure why but you can add it as a custom query in your Neovim config. I have yet to try this so you'll have to refer to the Neovim treesitter docs for where to add the query.

I'm not sure how to use this in Emacs, but there's also a tree-sitter grammar specifically for comment blocks, including TODOs: https://github.com/stsewd/tree-sitter-comment

you mean this one? https://github.com/stsewd/tree-sitter-comment

The reason I implemented this is because of the slow performance of tree-sitter-comment in large files. Treesitter will inject the comment language for every line comment, which is far from ideal. I've disabled the comment parser, but still wanted to see @something highlighted in Lua comments.

The right most window shows the code I want to query. This is a .cpp file, so the main-language is C++. For highlighting the two comments, I'm using tree-sitter-comment. This plugin injects the comment-language. I want to query all tag nodes from this injected language, but this query does not work.

You can install this parser for treesitter which highlights comments :)