Unable to display Floating Button in exclusively one tab - Using SlidingTabLayout and android.support.design

Question

I'm new to android app development and implemented a SlidingTabLayout. I want to display a floating button in one of the tab but unable to do so. I've tried including my button in my tab fragment as well as my main activity. In mainactivity, when I switch tabs, the buttons is still included in the second tab. I tried floatingbutton.show() and hide in my tab change listener but of no use. Any help will be appreciated.My activity_main.xml

<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawerlayout" android:layout_height="match_parent"
android:layout_width="match_parent">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.pegasus.tabstutorial.MainActivity">

    <include
        android:id="@+id/app_bar"
        layout="@layout/app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <com.pegasus.tabstutorial.SlidingTabLayout
        android:id="@+id/tabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/primaryColor" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:src="@mipmap/ic_launcher"
        app:layout_anchor="@+id/appbarLayout"
        app:layout_anchorGravity="bottom|right|end"
        android:layout_marginBottom="37dp"
        android:layout_alignParentBottom="true"/>

   </RelativeLayout>

   <fragment
    android:layout_width="280dp"
    android:layout_height="wrap_content"
    tools:layout="@layout/fragment_navigation_drawer"
    android:id="@+id/navDrawer"
    android:layout_gravity="start"/>

    </android.support.v4.widget.DrawerLayout>` 

and my home_tab.xml

    <?xml version="1.0" encoding="utf-8"?>
<RelativLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="You Are In Tab Home Tab"
    android:id="@+id/textView"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />

 </RelativeLayout>