According to the 0.9.4 release notes, “sliding windows” functionality is available for publishing:
There’s a new mode you can turn on called “sliding windows”. This overhauls your site’s navigation to open links beside the current page. Inspired from Andy Matuschak’s website https://notes.andymatuschak.org/
It would be really helpful if this mode could be made available directly in Obsidian, for all the same reasons it is helpful for vaults that are published to the web. Namely: being able to easily retrace the chain of links traversed in research and/or editing notes.