The narrator of this book is basically like a god who can see into the minds of many different characters. That means that we've got a straight-up Third Person Omniscient narrator on our hands here. Now, it's true that sometimes, Pasternak will decide to focus a single character, usually Zhivago, for long stretches. When being subjected to Liberius Mikulitsyn's endless Communist rants, for example, Zhivago thinks, "No, this is beyond anything! […] What infantilism! What shortsightedness!" (11.5.19).
That doesn't mean that we only get things from Zhivago's point of view, though. Heck, the book even goes on after the dude has died, so the narrator must look into the lives of other characters if the story is going to keep going. And if there's one thing this story does really well, it keeps going… and going… and—well, you get the point.