If you were a teeny 1" tall guy standing on the top of the shock mount in the picture above, and you turned around and looked at ABS system output, the bottom row has three brakeline outlets. The outlet which goes to the rear axle is the one on the left (driver's side/most outboard). Rear brakes share the same line. The other two outputs go to left and right front brakes.
You will quickly figure that out anyway when you start tracing the line from the rear axle forward. It runs next to the fuel line. Hope you have small hands or flare nut wrenches with a healthy bend in the handle. It's tight quarters.