I could provide a better help if I will know the Simulink scheme that you want to develop. I suppose that you want to add a filter to the reference to implement the 2DOF PI. Anyway, this webpage could be useful for your purposes:

https://es.mathworks.com/help/slcontrol/ug/designing-two-degree-of-freedom-pid-controllers.html

Best,

José Domingo

thanks for this orientation in my case I want to do a regulation of the DC voltage of a PWM-rectifier

You are welcome. The key point is what kind of scheme you want to build in Simulink to implement the 2DOF PI not the specific case in which it will be applied. If the scheme is similar that the one showed in the previous link you can use the Simulink block that is described in it.

Best regards,

José Domingo