How to get kp,ki,kd values using bode plot ? i need to design traditional controller (i have two Transfer Function system)

first i did linearization of the non-linear model, after that i got two Transfer functions from the linear model.

so, i want to use controller for these two transfer function (core power & Tave control);

Q1: please can any one explain this diagram (what's the CFF & CFB, is this PIDs or others controller ?)

Q2: how to get " use bode plot method to obtain the controllers ? (any answer, referance articles or books please)