Implementing Shor's algorithm on IBM Quantum Composer

I'm trying to recreate

from this paper in the IBM Quantum Composer. However, this circuit isn't enough understandable for me to do so.

I have tried to recreate the above circuit in the composer as follows

I've tried to recreate the following two gates for the MEF

as U(0,0,0,0) and nG2 where nG2 is

Obviously, I can be sure that my approach is wrong as I even don't know how to make one measurement affect the next one (recreate the lines conecting measurements with $$R_{\pi/2}$$ and $$R_{\pi/4}$$) and how to implement the MEF gates.

How should I recreate the given circuit in the IBM Quantum Composer to obtain the factors of $$N=15$$ ?