Don Brown is about the epitome of a "multiple defense" advocate as you can be. His base, or at least the foundation, of his defense is largely a two-high, "trap" coverage. He has lambasted a too frequent use of quarters coverage, while still incorporating many of the elements that make Cover 4 a favorite of many defensive coordinators across college football. And he runs single-high coverages like Cover 1 and Cover 3 as much as anything, and even in that area he's more multiple than his predecessor, as he incorporates a lot of different underneath coverage variations and backfield rotations that he's privy to because of the way he deploys personnel and the fact that he's so damn set in the fact that he's going to throw everything at you including the kitchen sink and the baby and the bath water and the Jabrill Peppers.
But he does all that, and as I said, maintains his two-high, Cover 2 base, relying heavily on his trap coverage (also used more and more frequently in the NFL, especially with how prevelent and dynamic the slot position is becoming). And he's that way because, out of a Cover 2, he's able to give the offense a ton of looks while maintaining the same base shell of a defense. It's the window dressing the Harbaugh uses with motions and shifts and formations, just on the defensive side.
All this to say: here's some of the many fundamental elements that Don Brown uses in his Cover 2 defense, including how he takes advantage of shifting personnel around pre and post snap in order to confuse the offense in combination with getting his guys in preferred positions.
(Note: this isn't a Don Brown-centric article, though it utilizes some of his diagrams, and he's really the only current DC in the B1G that uses Cover 2 as a base)