I've heard that 3-stair warps work by this method:
Anything in the middle columns warp you to Warp Spot 2, anything on the left warps you to Warp Spot 1, and anything to the right warps you to warp spot 3.

But how do they work if there's more than 3 Warps? The Warp Rings menu allows you to change the amount of warps in each Warp Ring, but I've never actually used a 3-stair warp before.