Is there a way to see all characters with a certain tag/filter characters by tag?

I’ve tagged most of the characters I’ve created, but there seems to be no way to see all the characters that have a certain tag. In the filters panel, I can only filter events by tag, not characters

Filters only apply to the data that is in the chosen view, so there isn’t a way to filter the character list on the left side panel.

You can choose to have your characters shown in Spreadsheet View, at which point you would be able to filter this view to show characters with a specific tag.

You can do this in Advanced Settings (Advanced Settings - Aeon Timeline 3 Knowledge Base)
Open Settings (the cog icon), then the Data Types tab, then Edit.
Click on “Character” in the list on the left, and select “Chronological order (always)” under the “Show in” heading on the right. You will also have to do this for “Character Group”.

Once this is done, characters will be displayed in spreadsheet view, and you will be able to filter them.