Most bris ceremonies include a number of guests present, beyond immediate family. Depending on how many guests, and depending on certain relationships beyond family and even with some rabbis, the ceremony could look very different from family to family in light of whom the parents of the baby might choose to have participate in the ceremony.
In Hebrew, the word כבוד (kavod) is often translated as "honor," thus the word for the honors given at a bris ceremony is Kibbudim. Those who are given these roles are the "honorees" in a sense, and every person in this category is described as "receiving a kibbud."
People often ask me to rank the kibbudim in their order of importance. This is very difficult to do once we get past the roles of father, mohel, and sandak - all of whom are defined in Jewish law and custom as "Baalei Bris" - those most involved in the fulfillment of the mizvah.
Some call the kibbud of holding the baby during the naming the "Standing Sandak" which adds a little pizzazz to a role of holding the baby. In particular if there are thankfully 2 grandfathers who are both present I typically recommend that this role be given to the grandfather who isn't serving as Sandak (the custom is to give the Sandak honor to a grandfather, and to switch for the second son).
Since in the Ashkenaz community it is uncommon to have a family repeat Sandaks for their subsequent sons, once the grandfathers have had the honor, additional sons tend to have different Sandaks who are relatives or friends of the parents.
After these two roles, every other kibbud consists of holding the baby for a brief period of time and can therefore be given to anyone (there are different views regarding women having roles beyond the kvatter and there is certainly a distinction to be made between a private home and, when doing the bris in a synagogue, respecting the rules of the particular establishment). Even within this realm of possibilities, some will certainly put more stock in a role connected to Eliyahu Hanavi (See also here: Defining "Kisei Eliyahu", versus even saying the brachot/blessings after the circumcision is completed.
Some put a lot of stock in the honor of naming the baby, which is why the role is often given to the family's rabbi.
Get your kibbudim planned and you're just about ready for your Bris Milah Ceremony!