Left Bar Navigation of Single Chapter via Headings

For those of us who like to write one long document rather than splitting text into separate 'chapters', it would be great if we could navigate using the nested headers/headings on the left menu as an alternative. (An example of similar functionality would be the Linux program Ghostwriter, which does this for markdown documents with headers.) Sudowrite already has standard headers/headings as needed for accessibility, so we're kinda already part of the way there!