"As in" is often used to clarify a term, give an example, and exaggerate.
Some illegal drug users, as in those who use cocaine, will have to submit to periodic surprise urine anaylis tests.
He is a medical doctor. By that I mean a real doctor, as in someone who has graduated from medical school, not someone who has taken a correspondence course from Thailand and now wears a white robe.
I am tired, as in I have not slept in 48 hours.
Yes, I would say that "as" could be replaced by "like".