tl;wr (too long; won’t read) — Is the function to limit the binder view in MacOS hidden, or is this just and iOS thing?
I seem to remember in iOS one could limit the binder view to just one folder. I write with a monolithic project structure which contains all works-in-progress (which is unfortunately many and diverse). Novels short and long, novellas, short stories, writing journal, nonfiction — it all goes in one project. I use to work with separate projects, but my work flow involves the interaction between too many simultaneous wip’s; doing it with separate projects badly interrupts flow. It would be nice though to be able to focus the binder down to a single wip when needed. I really like the way it’s handled in iOS. I’ve considered buying a new iPad pro and just doing everything in that, but the one single project is too large, with too many moving parts and too many words to efficiently sync. I think it would be a nightmare.