When I’m filtering with “my pipelines”, and click on a branch name, I get to the URL https://app.circleci.com/pipelines/github/[organization]/[project]?branch=[branch]&filter=mine. The filters shown correspond to this. However, the pipelines I actually see are the same as on “my pipelines”; the branch filter has no effect.
Related, but not the same, about inability to build the combined filter directly using “Filters”: https://discuss.circleci.com/t/pipeline-filter-is-not-working/40641