How change position of popup menu on android overflow button?

Applying gravity helped in my case

PopupMenu popup = new PopupMenu(this, v, Gravity.RIGHT);

To overlap only, use this approach:

PopupMenu popupMenu = new PopupMenu(getContext(), this, Gravity.NO_GRAVITY, R.attr.actionOverflowMenuStyle, 0);

To get a PopupMenu with a bright background and a detailed control over the offsets use this approach:

styles.xml

<style name="PopupMenuOverlapAnchor" parent="@style/Theme.AppCompat.Light">
   <item name="android:overlapAnchor">true</item>
   <item name="android:dropDownVerticalOffset">0dp</item>
   <item name="android:dropDownHorizontalOffset">0dp</item>
</style>

Code:

ContextThemeWrapper contextThemeWrapper = new ContextThemeWrapper(getContext(), R.style.PopupMenuOverlapAnchor);
PopupMenu popupMenu = new PopupMenu(contextThemeWrapper, this);

Add the following piece of code to your activity:

PopupWindow popupwindow_obj; // create object

popupwindow_obj=popupDisplay();  // initialize in onCreate()

popupwindow_obj.showAsDropDown(clickbtn,-40, 18); // where u want show on view click event

public PopupWindow popupDisplay() { // disply designing your popoup window
    final PopupWindow popupWindow = new PopupWindow(this); // inflet your layout or diynamic add view

    View view; 

    LayoutInflater inflater = (LayoutInflater)   getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

    view = inflater.inflate(R.layout.mylayout, null);

    Button item = (LinearLayout) view.findViewById(R.id.button1);

    popupWindow.setFocusable(true);
    popupWindow.setWidth(WindowManager.LayoutParams.WRAP_CONTENT);
    popupWindow.setHeight(WindowManager.LayoutParams.WRAP_CONTENT);
    popupWindow.setContentView(view);

    return popupWindow;
}

Create an XML in res/layout directory and name it mylayout.xml

<LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Window test" />
</LinearLayout>

After trying out each approach that I have found, I would think putting an anchoring view might still be an easier and simpler way, especially when you are using a more flexible layout, e.g. ConstraintLayout.

Just put an invisible view to where you want the popup menu to anchor:

<View
    android:id="@+id/anchor_menu"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_marginTop="10dp"
    app:layout_constraintStart_toStartOf="@+id/button_menu"
    app:layout_constraintTop_toBottomOf="@+id/button_menu"
    />

Then use it as the anchoring view instead:

    mPopupMenu = new PopupMenu(getActivity(), mPopupMenuAnchor);

Boom, it is done.