Nested Coordinator layout and Appbar Layout

Question

Trying to build layout in which the activity has Coordinator layout and Appbar layout. The appbar layout has tab layout, which is connected to a view pager. In the view pager, the first fragment has another coordinator layout and an appbar layout. When the scroll happens in appbar layout, I want the Activity's appbar layout also to scroll.

Activity's xml

    <?xml version="1.0" encoding="utf-8"?>


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

        <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/collapse_layout"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                app:layout_scrollFlags="scroll|snap|enterAlwaysCollapsed">


                <ImageView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:scaleType="centerCrop"
                    android:src="@drawable/material_flat"
                    app:layout_collapseMode="parallax" />


                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    style="@style/ToolBarWithNavigationBack"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:background="@android:color/transparent"
                    app:layout_collapseMode="pin"></android.support.v7.widget.Toolbar>
            </android.support.design.widget.CollapsingToolbarLayout>

            <LinearLayout
                android:id="@+id/tab_container"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerHorizontal="true"
                android:background="@android:color/white"
                android:clipToPadding="true"
                android:gravity="center"
                android:orientation="vertical"
                android:paddingTop="10dp"
                app:layout_scrollFlags="scroll|enterAlways|snap">

                <android.support.design.widget.TabLayout
                    android:layout_width="fill_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:layout_gravity="bottom"
                    app:tabIndicatorColor="#BDBDBD"
                    app:tabIndicatorHeight="4dp"
                    app:tabSelectedTextColor="?android:attr/textColorPrimaryInverse"
                    app:tabTextAppearance="@android:style/TextAppearance.Widget.TabWidget" />
            </LinearLayout>

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

        <android.support.v4.view.ViewPager
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_behavior="@string/appbar_scrolling_view_behavior" />

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

The fragment's xml

            <?xml version="1.0" encoding="utf-8"?>
             <NestedCoordinatorLayout 
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:background="@android:color/background_light">

<android.support.design.widget.AppBarLayout
    android:id="@+id/main.appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:color/white"
    app:theme="@style/ThemeOverlay.AppCompat.Dark">


    <LinearLayout
        android:id="@+id/home"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#e3e6e8"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="20dp"
        app:layout_scrollFlags="scroll|enterAlwaysCollapsed|snap">

        <android.support.v7.widget.CardView
            card_view:cardCornerRadius="4dp"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:layout_margin="24dp">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/shade_gradient" />

        </android.support.v7.widget.CardView>

    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="15dp" />
</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/simple.viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

     </NestedCoordinatorLayout>

When the appbar scrolls in the fragment, I want the activity's appbar to scroll also. I have used the NestedCoordinatorLayout as suggested in CoordinatorLayout inside another CoordinatorLayout Please let me know how to achieve that Thanks!