Hey Jarrett.
In Spanish we don't really have a translation for undergraduate research. I do research in Physics and I did undergraduate research during my bachelor's degree. The translation that Renzo gave you is correct "Investigación pre-grado". This is a new term that was developed not long ago. When I did my "undergraduate research" they called it "trabajo de investigación" (research project), but to be honest, everything in research is a research project, so I completely agree with the term "Investigación pre-grado", and I have heard other people use it.
On the other hand, "Trabajo de Fin de Grado (TFG)" means "Bachelor Thesis". Actually, a bachelor thesis doesn't have to be research in many cases.
I hope this helps!