I have found out CDFs of 2 data and listed them. I need to find out the composition of such 2 CDFs

X = RandomVariate[ExponentialDistribution[2], 10]  Y = RandomVariate[ExponentialDistribution[3], 10]  f = EmpiricalDistribution[Y]  fy = CDF[f, t] // PiecewiseExpand  g = EmpiricalDistribution[X]  fx = CDF[g, u] // PiecewiseExpand 

I want to find the composition fx of fy.