MainWindow.xaml

<mah:MetroWindow x:Class="HamburguerConMvvm.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:mah="http://metro.mahapps.com/winfx/xaml/controls"
        xmlns:iconPacks="http://metro.mahapps.com/winfx/xaml/iconpacks"
        xmlns:converters="clr-namespace:HamburguerConMvvm.Converters"
        xmlns:views="clr-namespace:HamburguerConMvvm.Views"
        xmlns:viewModels="clr-namespace:HamburguerConMvvm.ViewModels"
        xmlns:local="clr-namespace:HamburguerConMvvm"
        mc:Ignorable="d" WindowStartupLocation="CenterScreen"
        Title="MainWindow" Height="450" Width="800">

    <Window.DataContext>
        <viewModels:MainViewModel />
    </Window.DataContext>
    
    <Grid>

        <Grid.Resources>
            <converters:SelectedItemToContentConverter x:Key="SelectedItemToContentConverter" />

            <!--  this is the template for the items (options too)  -->
            <DataTemplate x:Key="MenuItemTemplate" DataType="{x:Type mah:HamburgerMenuIconItem}">
                <Grid x:Name="RootGrid"
                      Height="48"
                      Background="Transparent">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type mah:HamburgerMenu}}, Path=CompactPaneLength}" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <ContentControl Grid.Column="0"
                                    HorizontalAlignment="Center"
                                    VerticalAlignment="Center"
                                    Content="{Binding Icon}"
                                    Focusable="False" />
                    <TextBlock Grid.Column="1"
                               VerticalAlignment="Center"
                               FontSize="16"
                               Text="{Binding Label}" />
                </Grid>
                <DataTemplate.Triggers>
                    <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type mah:HamburgerMenu}}, Path=IsPaneOpen}" Value="False">
                        <Setter TargetName="RootGrid" Property="ToolTip" Value="{Binding ToolTip, Mode=OneWay}" />
                    </DataTrigger>
                </DataTemplate.Triggers>
            </DataTemplate>
        </Grid.Resources>
        
        
        
        <mah:HamburgerMenu x:Name="HamburgerMenuControl"
                                IsPaneOpen="True"
                                ItemTemplate="{StaticResource MenuItemTemplate}"
                                SelectedIndex="0"
                                DisplayMode="CompactInline">

            <!--  Items  -->
            <mah:HamburgerMenu.ItemsSource>
                <mah:HamburgerMenuItemCollection>
                    <mah:HamburgerMenuIconItem Icon="{iconPacks:Material Kind=Home}"
                                                     Label="Home">
                        <mah:HamburgerMenuIconItem.Tag>
                            <DataTemplate>
                                <views:HomeView DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=mah:MetroWindow}, Path=DataContext.HomeVM}" />
                            </DataTemplate>
                        </mah:HamburgerMenuIconItem.Tag>
                    </mah:HamburgerMenuIconItem>

                    <mah:HamburgerMenuIconItem Icon="{iconPacks:Material Kind=AccountKey}"
                                                     Label="Customer">
                        <mah:HamburgerMenuIconItem.Tag>
                            <DataTemplate>
                                <views:PrivateView DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=mah:MetroWindow}, Path=DataContext.PrivateVM}" />
                            </DataTemplate>                            
                        </mah:HamburgerMenuIconItem.Tag>
                    </mah:HamburgerMenuIconItem>

                    <mah:HamburgerMenuIconItem Icon="{iconPacks:Material Kind=MessageAlert}"
                                                     Label="Dialogs">
                        <mah:HamburgerMenuIconItem.Tag>
                            <DataTemplate>
                                <views:DialogsView DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=mah:MetroWindow}, Path=DataContext.DialogsVM}" />
                            </DataTemplate>
                        </mah:HamburgerMenuIconItem.Tag>
                    </mah:HamburgerMenuIconItem>
                </mah:HamburgerMenuItemCollection>
            </mah:HamburgerMenu.ItemsSource>
            
            <!--  select the tag (ViewModel) of the selected item (options item)  -->
            <mah:HamburgerMenu.ContentTemplate>
                <MultiBinding Converter="{StaticResource SelectedItemToContentConverter}">
                    <Binding FallbackValue="{x:Null}"
                             Mode="OneWay"
                             Path="SelectedItem.Tag"
                             RelativeSource="{RelativeSource Self}" />
                    <Binding FallbackValue="{x:Null}"
                             Mode="OneWay"
                             Path="SelectedOptionsItem.Tag"
                             RelativeSource="{RelativeSource Self}" />
                </MultiBinding>
            </mah:HamburgerMenu.ContentTemplate>
        </mah:HamburgerMenu>
    </Grid>
</mah:MetroWindow>