5.5e and 5e filters

Am I missing something or is there no way to filter the marketplace by 5.5e or 5e books?

This seems pretty massive so I assumed it was possible, but I can't see any way to do it!

Thanks!

There is not.

You can filter like that on the Library screen, which does include all the digital books on the marketplace site. It's not great, but it's something.

Frankly, the current marketplace site is a bit of a mess, and wasn't designed well. It's missing several pretty obvious features that would make using it a lot easier (including what you're suggesting and the ability to filter out stuff you already own) and it's organized in a weird way that can make it quite difficult to find anything.