I think he means in the GUI:
Stabilization -> Advanced -> Settings Bank 1(2,3) -> Max Rate Limit
This makes all functions (roll/pitch/yaw) move more slowly
Problems like you have are usually caused by an imbalance somewhere. CG not in center, different strength motors / props, ESCs not calibrated (or neutrals not correct). Also, you should try disabling "pirouette compensation" on that same advanced page.
Yaw seems to be your main problem, so reducing the yaw PID is a good idea. Also reducing the yaw max rate.
You set up an "Actuators" scope on the scope page and watch what happens when you yaw hard but just small enough to not go crazy. What you should see before the yaw is all 4 motors working equally hard (all 4 lines in the same place). At the beginning of the yaw, two lines should go up as a pair together and 2 lines should go down.
What you are going to see before and during the yaw is one or more motors working harder than the others. That will at least tell you which motors are weak.
After disabling pirouette compensation, I would start with ESC recalibration (and neutrals), and moving the battery pack away from the weak motors so the stronger motors carry more weight (regardless of CG).