See Boards That are Linked to Projects

@Andy Turner - As you have noticed, there is no filtering options for columns in the dashboard (board, online, owner, project, starred).

Options now…

Wish List

You could request this feature by creating a Wish List Idea post. There is a similar idea where the user wanted to filter on just the “online” column. You could add your comments/vote, but I would suggest creating your own, more generic post. You can create Idea in the Wish List category by following the guidelines here: Wish List: Everything You Need to Know.

If you do create a Wish List Idea post, I would also recommend that you post a link to it back here, so that future readers of this post can quickly get to and vote for your Idea.

Lastly, don't forget to vote for your own Idea.

Miro Developer Platform

It may be possible to use the Miro Developer Platform API to return a list of boards that are not a project. This could be an MVP and could be expanded to include more options. You would probably want someone with a development background to review t API he developer platform documentation.