You can do this with URL parameters. There is no point-and-click interface for this that I know of.
Here are all observations that you have ID’d as European swallow-wort:
https://www.inaturalist.org/identifications?taxon_id=632667&user_id=plantarum
For this to work, you need the taxon_id of whatever taxon you’re looking for. If you look at the taxon page for v. rossicum, https://www.inaturalist.org/taxa/632667-Vincetoxicum-rossicum, you find its taxon_ID in the URL. It’s 632667.
Generally, there’s a topic here on the forums that goes into more depth of how to use the URL parameters than I could explain: https://forum.inaturalist.org/t/how-to-use-inaturalists-search-urls-wiki/63/92