I enjoy using OnlyOffice. I have some rather large documents and easy navigation is essential. It would be useful if a Sidebar could be an option, containing a Table of Contents in Tree fashion that would allow you to click on an item and be taken to the linked location in the document.
Hello @rnbw
Headings menu on the left toolbar has a tree of all chapters in the document formatted as headings. Please see the documentation on that in our Help Center:
If it is not what you are looking for, please elaborate on your query.