On this following circuit shown in the schematic diagram, two MAX455s IC chip are cascaded to build a 1 of 15 video Multiplexer. This cascading is done by connecting the output of one MAX455 MUX to one input of  a second MAX455 MUX. The output of the first MUX should be terminated to ground using a 75R resistor, to preserve bandwidth although the two devices are usually close to one another.

1 of 15 cascaded video mux circuit schematic