It seems that most natural antifungals from the plant kingdom are also antibacterial and often antiviral, like oregano oil, gse and olive leaf. The plant kingdom have a symbiotic relationship with bacterias and fungus just like we do.
I think these symbiotic organisms are quite similar to those found in our intestinal tract (and skin), such as the lactobacilli species found on cabbage (and in greater concentrations in sauerkraut). So the antimicrobial they produce are probably made to defend them against the same types of bacterias we don't want.
About GSE: "However, while one study found that Grapefruit-Seed-Extract
significantly inhibited E. coli, another normal inhabitant of the GI tract, it left the important and beneficial Bifidobacteria unchanged, and only slightly reduced the Lactobacilli species."
For specific bacterias, fungi and molds, all other different organisms are enemies. Nystatin, made from a mold, will logically tend to have a very broad spectrum antifungal effect. It's probably the most effective against fungi that ferment the same sugars and live in a similar pH. So when it kills candida, I'm pretty sure it will also kill its yeasty competitors.