Sounds similar to the painless wiring harness. You can download their manual
HERE and see if it is the same.
Basically the power goes from the fuse box to the brake sensor, to the column. The internal guts of the column determine when to add power to either both lights (brake only) or to flash one (turn signal on). The column output wires should be labeled depending on where they go. It depends if you are having both lights on each side flash as one or having one be brake only and the other only work as a flash/turn signal.
Painless's diagram isn't great but hopefully you can see how it is supposed to be done. The magic of low light (parking indicators), high light (brakes), or flashing happens inside the column circuitry.
White wire comes in from the brake switch.
Purple wire provides 12v+ flashed power to the column.
Yellow and Green are output wires to the brake lights.
If the white wire is hot (brake pedal is pressed), both "brake" wires get 12v+
If the turn signal switch is pushed up or down, the one brake light is flashed - purple wire signal (flashed) is passed to the brake light on the side selected so that light flashes.
If both the brake is pressed and the turn signal is engaged, the flashed signal is passed to the correct side (turn/flashing) and the white wire signal is passed to the other side (brake/constant).
The front lights are easier since they aren't pulling multiple duties.