Dont' understand the question. In the US, "undergrad" means 4 years of college or university, i.e. a Bachelor's degree. The only difference between a college and a university is that a college offers a 4 year degree only, but a university also offers "graduate" degrees, taken after the 4 year degree, such as a Masters, a PhD, or a professional degree such as law or medicine.
So you can go to "college" at either a college or a university. All law schools that I know of require as a prerequisite a 4 year Bachelor's ("undergraduate") degree. No school requires an advanced degree beyond that. Law School IS the advanced degree. Does this help?