Etymology, ubiquity and synonyms of the phrase "Tribal Knowledge"
Solution 1:
Tribal Knowledge is a term that can be used everywhere, because a tribe is basically a group or subgroup of people, not necessarily a division of an race. This word can be used like in this situation.
It is only generally used around corporations, businesses, offices, etc.
Synonyms include:"institutional memory," or as Martin suggested in a comment above,"institutional knowledge"
But neither of them are as well-known as tribal knowledge.
Solution 2:
As I was reading your question a great near-synonym jumped into my mind that I first encountered in A Confederacy of Dunces: “folkways”.
If that provides a different colour to what you're looking for, I would also suggest “lore” as having different overtones to the “folklore” that another contributor already provided.