hey,
You may pick any hospital or outpatient settings for both elective and core selective, meaning they dont have to be "affiliated hospitals". the only difference is that for elective: you may choose any specialty or primary care you like, lets say orthopedics or family med. but for core selective you need to pick only from I think: surgery, fam med, IM, Peds, Ob gyn, Psych only but at any hospitals or clinics, or offices.