Your dishwasher has a separate drain pump (AP4364233) that draws water from the sump and pumps it into the drain line. There is no filter, but there is a flapper valve that can be reached from inside the sump area. If the dishwasher is not draining, verify you can hear the drain pump running, and you may want to remove the drain hose and run some water through it to make sure it is not blocked.