Where should ‘app:layout_behavior’ be set?

Check this link: https://developer.android.com/reference/android/support/design/widget/AppBarLayout.html

AppBarLayout also requires a separate scrolling sibling in order to
know when to scroll. The binding is done through the
AppBarLayout.ScrollingViewBehavior class, meaning that you
should set your scrolling view’s behavior to be an instance of AppBarLayout.ScrollingViewBehavior. A string resource containing the
full class name is available.

They mentioned about that, it should be the View which will be shown under the AppBarLayout like this:

<android.support.design.widget.CoordinatorLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent">

     <android.support.v4.widget.NestedScrollView
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             app:layout_behavior="@string/appbar_scrolling_view_behavior">

         <!-- Your scrolling content -->

     </android.support.v4.widget.NestedScrollView>

     <android.support.design.widget.AppBarLayout
             android:layout_height="wrap_content"
             android:layout_width="match_parent">

         <android.support.v7.widget.Toolbar
                 ...
                 app:layout_scrollFlags="scroll|enterAlways"/>

         <android.support.design.widget.TabLayout
                 ...
                 app:layout_scrollFlags="scroll|enterAlways"/>

     </android.support.design.widget.AppBarLayout>

 </android.support.design.widget.CoordinatorLayout>

My question is: in what exact ViewGroup (or maybe View) should we put
that app:layout_behavior?

And in this link: http://guides.codepath.com/android/Handling-Scrolls-with-CoordinatorLayout

Next, we need to define an association between the AppBarLayout and
the View that will be scrolled. Add an app:layout_behavior to a
RecyclerView or any other View capable of nested scrolling such as
NestedScrollView. The support library contains a special string
resource @string/appbar_scrolling_view_behavior that maps to
AppBarLayout.ScrollingViewBehavior, which is used to notify the
AppBarLayout when scroll events occur on this particular view. The
behavior must be established on the view that triggers the event.