module for multiply speed

I’m trying to develop a module for taking the speed from layer1, multiply that by (f.ex) 2 and use the multiplied speed for layer2.

So f.ex if I move the layer1, the layer2 would move twice the speed if the multiplier would be 2.

When I’m thinking about it, it doesn’t sound so hard, but I might be way off.

If anybody has a solution or a script, I’d be happy to hear that!