How to reference current item when style is applied

[sam-wheat]

In the XAML below I want to pass the ListBoxItem to which the style is being applied to the converter. What I am getting is an instance of MainWindow. Why is this true, and how do I reference the ListBoxItem to which the style is being applied?
For the record, this problem is mostly academic. I am aware the converter is unnecessary - I am trying to solve a different problem and ran into this along the way.

Example project attached.

    <Style TargetType="ListBoxItem" x:Key="zzz">
            <Setter Property="IsSelected">
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource SelectedItemToBoolConverter}">
                        <Binding Path="." />
                        <Binding RelativeSource="{RelativeSource AncestorType=ListBox}" Path="." />
                    </MultiBinding>
                </Setter.Value>
            </Setter>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ListBoxItem">
                        <CheckBox Margin="5,2" IsChecked="{TemplateBinding IsSelected}">
                            <ContentPresenter />
                        </CheckBox>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </StackPanel.Resources>


    <ListBox ItemContainerStyle="{StaticResource zzz}" >
        <ListBox.Items>
            <ListBoxItem Content="Item 1"/>
            <ListBoxItem Content="Item 2"/>
            <ListBoxItem Content="Item 3"/>
            <ListBoxItem Content="Item 4"/>
            <ListBoxItem Content="Item 5"/>
        </ListBox.Items>
    </ListBox>

Converter:

public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
 {
     ListBoxItem lbi = values[0] as ListBoxItem; // Expected: ListBoxItem  Actual: MainWindow
     ListBox lb = values[1] as ListBox; 
     return lbi == lb.SelectedItem;
 }

CommandProblem3.zip

[batzen]

You have to bind to RelativeSource=Self instead of ".". "." references to the current DataContext instead of an UI element.

[sam-wheat]

Thank you @batzen!