Originally Posted by
bianzongao
But I can online point 6 trips in the multi-city. There is a screenshot I saw from AMS-YUL, one way includes 5 stops.
You do it in the advanced routing codes field, not using multi-city.
So for example searching for AMS-YUL, in the advanced routing field you could put in:
LHR HEL ORD PHL
and that will get you that nice convoluted itinerary. You can also put int "f bc=i" in the advanced field on the right if you are looking for an I fare.