You could make successive observations on the plant, each with a different interaction. Instead of trying to make one observation have 5 associations, the 5 observations would each highlight a different species interaction. You could also link the observations together as an “observation set” and perhaps even put a link to the observation set in the description.
https://forum.inaturalist.org/t/using-the-field-similar-observation-set-for-linking-observations-of-lepidoptera-when-raising-on/1018