Finding the Content of a ContentPresenter and setting styles

Question

I couldn't find an appropriate topic for my problem. I have the following code.

<ContentPresenter x:Name="ContentPresenter"
                  VerticalAlignment="Center"                      
                  Width="Auto"/>
<TextBox x:Name="TextBlockFront" >
    <TextBox.Style>
        <Style TargetType="TextBox">
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding ElementName=TextBlockFront, Path=IsFocused}" Value="true"/>
                    <Condition Binding="{Binding ElementName=ContentPresenter, Path=ContentProperty}" Value="ComboBox"/>
                    </MultiDataTrigger.Conditions>
                    <Setter Property="Visibility" Value="Hidden"/>
                    <Setter Property="Text" Value="{Binding ElementName=ContentPresenter,Path=SelectedItem}"/>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>
    </TextBox.Style>
</TextBox>

I want to get the clarification about the second condition of my MultiTrigger. I am relative new to WPF and I would appreciate any help in sorting out my doubt.

Expected behaviour:

when the TextBox is focused AND the ContentPresenter is ComboBox then I want to set the above properties. If the ContentPresenter is TextBox then I will set the Text property instead of SelectedItem