Is it possible to have a submenu in SimpleToolkit?

[Hoosje1958]

I've added x:Name to the Tab and IsVisible="True"

<Tab
    Title="My Post"
    x:Name="MyPost"
    IsVisible="True"
    Route="MyPostTab"
    Icon="document_bar.png"
    FlyoutIcon="{AppThemeBinding Light=document.png, Dark=document_dark.png}">
    <ShellContent
        Title="My PostP"
        ContentTemplate="{DataTemplate pages:MyPostPage}"
        Route="MyPostPage"/>
</Tab>

In the AppShell procedure "ItemClicked" I programmatly set this tab "IsVisible = False"

But this do not work.
Is there a possiblity to create a Sub menu?