ControlValueAccessor I am using deeply nested Custom Component, How to pass value from last Child-3 to the parent Component

Question

I tried to mimic the folder structure as similar to my application. Shared a stackBlitz link

https://stackblitz.com/edit/angular-ivy-61duhd?file=src/app/child-1/child-1.component.html

Expected: When printFormParent() clicked, I need to see the value of the input field from the child-3-a and child-3-b components.

How to pass the value of nested reactive forms? What am i missing?