Equivalent to Scrivener notes sidebar?

I've been working in Scrivener on a book I'm researching but in (almost) every area I feel Obsidian could be more useful for me. One thing I'm missing: for any given bit of writing I'm working on, to have a sidebar of all my research notes and thoughts for that idea. In Scrivener, you create documents (their equivalent of a note), which has a writing pane for your actual content, and a separate pane of notes on the side.

I know I can display a note for the actual writing + a separate note side by side in Obsidian, or I could create an MOC which is a compilation of all those sidebar notes for a given topic. But in a Scrivener document, the sidebar notes are part of the document, yet distinct from the actual writing in the main writing pane.

Basically, when I'm writing on a specific topic, I want to have all my notes/research about that topic right there next to it. But I want them to stay "pinned" to that specific topic document/note.