DataTrigger XPath condition on tag

Question

I have a XML file nodes.xml which I would like to show in TreeView

<?xml version="1.0" encoding="utf-8"?>
<nodes>
    <node1 attr1="val1"/>
    <node2 attr2="val2"/>
</nodes>

Every node should be shown, attr1 of node1 and attr2 of node2 I want to put in one element. So I make a conditional TextBlock but don't know how to make condition like Binding = Tag Value = "node2"

<Window.Resources>
    <XmlDataProvider x:Key="nodes" Source="nodes.xml" XPath="nodes/*"/>
</Window.Resources>
<Grid>
    <TreeView ItemsSource="{Binding Source={StaticResource nodes}}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding}">
                <TextBlock>
                    <TextBlock.Style>
                        <Style TargetType="TextBlock">
                            <Setter Property="Text" Value="{Binding  XPath=@attr1}"/>
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding XPath=???}" Value="node2">
                                    <Setter Property="Text" Value="{Binding XPath=@attr2}"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </TextBlock.Style>
                </TextBlock>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>
</Grid>

I'm almost sure that replace ??? with something like "Tag" will be enough because this condition with attribute value for example works fine. name() doesn't work.