Implicit differentiation, its derivative

Question

I'm unsure how the derivative comes out in the following. I have a parametrization $t'=f(t)$ and a parameter $x(f(t))$ and I'm taking: $\frac{d}{d(f(t))}x(f(t))$. I'm not sure if the derivative would come out as $ \frac{df(t)}{dt} \frac{d}{dt}x(t) $ or something else.