Navigation drawer menu item only clickable ubtitle

I'm trying to my menu but I have a problem, I would like to habe smt like that

that's my code

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:title="Subtitle 1">
        <menu>
            <group android:id="@+id/group1">
            <item
                android:title="Item 1 "/>
            <item
                android:title="Item 2"/>
        </group>
        </menu>
    </item>

    <item android:title="Subtitle 2">
        <menu>
            <group>
                <item ></item>
            </group>
        </menu>
    </item>


    <item android:title="Subtitle 3">
        <menu>
           <group>
            <item
                android:title="Item 1"/>
            <item
                android:title="Item 2"/>
            </group>
        </menu>
    </item>
</menu>

I don't know exactly how to handle it, when I run this code I got that, I shouldn't have the empty space and subtitle 2 has to be clickable

Someone can help ? Thx