The 'tags' section is for the tags applied to posts, not users who posted/responded to it. In the Filter section on the left side of the main page are filters for stuff you posted (My Content) and questions you are following but haven't posted to. Is this not sufficient?
TBH I struggle trying to find posts I've responded to as well. For recent posts it is OK but sometimes I remember answering a question from months ago and trying to find that post again is awful. Search tends to pull in way too many unrelated responses and the sorting options for My Content is limited to updated, created and answers which is useless for posts over a couple days old. I'd really like to see an improved UX to allow me to quickly find specific posts I have responded to before without having to search the entire site or scan through 100s of pages of results.