Originally Posted by
Clay_C.
I assume this would entail meeting the ride at a nearby train station instead of the airport, but I cannot find any explanation as to how this works.
That's not how it works. You have to travel from one of the last stations of one of the applicable subway lines to a destination that is no more than 2.5 km away from that station - downtown Berlin is much farther. It is easier and cheaper to take the train to a station near your destination and take a cab from there.