The Bigger Good, is a phrase used to identify a character who is a greater paragon than the main character or characters, who usually qualify as simply the "Big Good". The Bigger Good as opposed to the Big Good usually is not the focus of the story but a truly benevolent force which keeps most other aspects of the world in order or outright apes the main heroes' current achievements. Since not being a main hero themselves, the Bigger Good is both more important to the world at large than the main heroes but also out of focus from the heroes' main exploits.
The Mentor: On occasion when a Big Good's mentor has set them out on their hero's arch and made them what they are, the mentor in question may be considered a Bigger Good. Heroes such as Yoda are the best examples of this.
The Role Model: It is fairly common for some heroes to be following in the foot-steps of another, on the occasion that the role model is both genuinely benevolent and has never been a main character themselves these heroes fall into the realm of Bigger Good. This can be seen with heroes like Billy from Adventure Time with Finn and Jake or High Summoner Braska of Final Fantasy X.
The God: Sometimes a Bigger Good is established to show that in the larger scope of things, good is still being maintained by a force beyond the struggles of mere mortals. Heroes like God from the Bible or Raava from Legends of Korra are excellent examples of this.
The Good King/Queen: Good Kings, Queens, Leaders etc are fairly common in works of fiction however when the authority figure in question is both undeniably good and actively on the same side as the main-heroes they cross into the realm of Bigger Good. This can be seen with heroes such as Princess Celestia of My Little Pony: Friendship is Magic.