You might be able to do it with https://github.com/IBM/tree-sitter-codeviews https://github.com/IBM/tree-sitter-codeviews - though the screenshot in the readme

You might be able to do it with https://github.com/IBM/tree-sitter-codeviews https://github.com/IBM/tree-sitter-codeviews - though the screenshot in the readme is in much more granular detail than class/ER diagram. I'd be surprised if there isn't a nice way to do this with tree-sitter or LSP, not to mention some language-(..theist?! Not language-agnostic) ways.