One way of doing this, seems to be to remove header and footer. Then you seemingly have to create the menu manually for each page.
Also the video doesn’t show how to make the sidebar fixed etc.
I was hoping I could add dynamic sticky menu to the main/right area, and keep a fixed left sidebar.
If I can make my own snippet/widget for the sidebar, that should be doable. But I’m not sure Blocs’ included automatic menus, without turning on header/footer (which would break this setup) …