Even when you have multiple POVs, you have ONE protagonist. ONE antagonist. (At least for the story as a whole; within a scene, there can be a different protag or antag form time to time; you'll have a different temporary protag for a subplot, and you may have a different scene antagonist, who's pushing or pulling the protagonist into the path of the overall antagonist).
So, even though Terry Pratchett writes in omniscient, and uses many, many heads over the course of the story, there is one clear protagonist for the story as a whole, and several secondary plots that all come together at the end.
In third limited, the protagonist will have the pov of the major scenes -- beginning, turning points and ending. Intermediate scenes may be in other POVs, either for subplots or for revealing information that the protagonist isn't on-scene for or whatever. And you'll wrap up the secondary POVs, either in a mirror image to the way you introduced them (e.g., Main character is in first scene, Character A is POV in the third scene, Character B is POV in the fourth scene; and then for the wrap-up, Character B is wrapped up first, then Character A, and finally the Main character). Or, at least, that's a starting point. And you may not need to be in the secondary character's POV to wrap it up, if, say, it's a romance, so the secondary character is the hero, and you already know what he wants, and so if he gets what he wants in the final scene in the heroine's POV, or if we know he won't say "I love you" until he's come to grips with X, and he does say "I love you," then we know his loose ends are also wrapped up. Not all loose ends have to be wrapped up INSIDE the character's head for us to know that they're wrapped up.
JD