[ricg]

I'm working on something like this (macOS/iOS), although it is not quite ready yet.

Notes can have tags and attributes so you could have attributes per note like: topic=rocketscience, semester=fall2020. Later you could say: "sort all my notes by semester and then group by topic" or if you change your mind, set up a second view for "all notes grouped by topic then by semester".

If you're interested, feel free to contact me through the site (kitestack.com/lnotes). I'd love to learn more about how you currently organize your notes.