A more general term used for any component of a culture or a subculture is a folkway including both its beliefs and its practices. Merriam-Webster defines it as follows:
a mode of thinking, feeling, or acting common to a given group of
people; especially: a traditional social custom
The sum total of all of the beliefs of a culture or a subculture is called a worldview. Tenet is a synonym for belief and probably closer to what you are looking for if "belief" is insufficiently technical and precise in its meaning. A worldview is:
A worldview is a network of ultimate beliefs, assumptions, values, and
ideas about the universe and our place in it that shapes how a person
understands their life and experiences (and the lives and experiences
of others) and how that person acts in response.
Ethos mentioned above, is really a synonym of "worldview" and not of a specific belief or tenet.
Some synonyms for tenet include: principle, belief, doctrine, precept, article of faith, axiom, canon, premise, conviction, view, opinion, position, and teaching.
The term dogma has a primarily religious connotation and is also mildly pejorative when not used in strictly technical sense by religious scholars and clergy.
A "core-value" is often call a norm and differs somewhat from a belief as it is a moral or ethical prescription or value, rather than a belief about what something is. A "norm" is defined as:
a standard or pattern, especially of social behavior, that is typical
or expected of a group. "the norms of good behavior in the civil service"
The plural of "norm" in this sense is "norms". It can also be called a convention (as in a social convention).
The term "norm" is a preferred term to describe a particular value of a culture or sub-culture in anthropology and sociology and cultural psychology.