In addition to naming people in photos, I use the Keywords field to add further information.
One Keyword is "Family". So, by selecting this for appropriate photos, I can locate/list/view all photos that contain Family based on just this keyword -- I don't need to keep track of all the family member names in an expression.
In fact, I have a Smartlist view "Family" that lists everyone alphabetically, but since it selects on Keywords=Family it only includes those people/photos.
I use many other Keywords, such as Birthday, Holiday, Wedding, Home, Office, etc.
So, to see all Family photos of Birthdays, but no other photos, I just select on these two Keywords.
(Yes, Birthday could be an Event tag. I my library I use Event for more specific info, such as "Bubba's Birthday" so I can find all the photos of that.)