Can't figure out how to filter by tag

How do I filter articles by tag? It seems that the tag cloud displays only some, presumably most popular, tags.

If I understand you correctly, you’re asking about this:
Screenshot%20from%202018-05-18%2007-08-14

This screenshot is from Preferences -> Filters -> Create filter -> Add (Match)

Thanks, but no, I meant something else: how to display all articles with a given tag already assigned.

oh… ok - then click on the tag on one of the articles you want, this will trigger a search for all articles with that tag. Then you can use the generated RSS feed and subscribe to it (i.e. subscribe to search - hit the RSS icon at the top of the page, next to the search terms).

That worked. Thank you.