teachers', students', and administrators' experiences
teachers,' students,' and administrators' experiences
? I think it is the first example with apostrophe, then comma?
The comma does not go inside the apostrophe. And you have too many commas.
It is OK to say
teachers', students' and administrators' experiences...
That is, your second comma is not needed, unless you are devoted to the Oxford Comma.
The 'Oxford comma' is an optional comma before the word 'and' at the end of a list: We sell books, videos, and magazines. It's known as the Oxford comma because it was traditionally used by printers, readers, and editors at Oxford University Press.
It would be neater to say:
The experiences of teachers, students and administrators...