This other feature request may be considered as a superset of the present one:
https://forum.inaturalist.org/t/ideas-for-a-revamped-explore-observations-search-page/8439/155
This tool (a desktop application using the iNaturalist API, for reviewing and identifying observations) provides an easy access to all ancestors of a selected taxon:
https://forum.inaturalist.org/t/amount-of-unknown-records-is-decreasing/8594/457