Choose Custom in the drop down time menu. Click on the Rating Options button that pops up. You have to choose at least + or - 25 though or they won't help you find a game.
https://support.chess.com/customer/portal/articles/1622811-how-are-seeks-matched-in-live-chess-
How can I filter out player which have rating below some value? I set min rating on Play tab but it is not working.