This a 22d. "Product of the numbers before and the one after."
The answer is "four". Is it because the two numbers in the number of the clue are 2 and 2 and 2x2 =4 but regardless where does "and the one after " fit in, please?
I suspect the clue reads "22 Product of the numbers before and the one after (4)", the enumeration being what the '[,] and the one after' refers to; the 2x2 [=4] as you say comes from the clue number.