Continuity mistake: At the dinner scene at Bilbo's house, just before Bofur throws the egg at Bombur's mouth, Fili is seen sitting next to Bombur. Yet as Bombur catches the egg, Ori is now sitting where Fili was sitting.
Continuity mistake: Just after Radagast has a flashback of him seeing the Necromancer, some of the white stuff on his beard disappears briefly in the shot where he inhales the stuff in Gandalf's pipe. (01:15:20)
Continuity mistake: When Bilbo brings the two bowls of stew for Fili and Kili there's a spoon in each of the bowls, but after Bilbo sets down the bowls one of the spoons has vanished when he picks up the bowls again in the closeup, but the spoon reappears when they run after the Mountain Trolls.
Answer: Hobbiton is the village where Bilbo was born. Overhill is on the northern edge of Hobbiton and Underhill is at the bottom of said hill. Built into the hill itself is Bag End, the Baggins estate. The Shire is the name of the Hobbit lands overall. So, he's from the village of Hobbiton in The Shire, and his home is Bag End, which is in the midst of the hill that forms both Overhill and Underhill.
Captain Defenestrator