Add custom view to the right of toolbar

Given answers work but if you want to set a title to the toolbar (most likely you will), then adding a RelativeLayout pushes the title out of view to the right. In this case you need to disable the toolbar title by setting getSupportActionBar().setDisplayShowTitleEnabled(false) and add a custom TextView next to the other view you wish to add to Toolbar. So as an example you would add a ImageView this way:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
    android:id="@+id/base_activity_toolbar"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:elevation="4dp"
    android:minHeight="?attr/actionBarSize"
    android:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/custom_toolbar_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            style="@style/ActionBarTitle"/>

        <ImageView
            android:layout_width="20dp"
            android:layout_height="20dp"
            android:scaleType="centerCrop"
            android:adjustViewBounds="true"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@id/custom_toolbar_title"
            android:src="@drawable/arrow"/>

    </RelativeLayout>

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

You can add ViewGroups inside Toolbar

          <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="@dimen/toolbar_height"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <RelativeLayout
             ....
            </RelativeLayout>

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

I just set layout_gravity to the rightand it worked

  <android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="0dp"
    android:layout_height="?android:actionBarSize"
    app:title="NEW REQUESTS"
  >
    <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="blahblah"
      android:layout_gravity="right"  
      />
  </android.support.v7.widget.Toolbar>