Treeview with data type dependent header and items

I'm looking for a TreeView structure of:

> {Name} {ParentButton}
 > ParentData.Text
 > {Name} {ChildButton}
  > ChildData.Text
  > {Name} {ChildButton}
   > ...
> {Name} {ParentButton}
 > ParentData.Text
 > ...

I've come up with the following:

<TreeView ItemsSource="{Binding Models}">
  <TreeView.Resources>
    <HierarchicalDataTemplate DataType="{x:Type models:ParentModel}" ItemsSource="{Binding Children}">
      <StackPanel Orientation="Horizontal">
        <Label Content="{Binding ParentData.Name}"></Label>
        <Button Content="MyParentButton" Command="{Binding ParentButton}"></Button>
      </StackPanel>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="{x:Type models:ChildModel}" ItemsSource="{Binding Children}">
      <StackPanel Orientation="Horizontal">
        <Label Content="{Binding ChildData.Name}"></Label>
        <Button Content="MyChildButton" Command="{Binding ChildButton}"></Button>
      </StackPanel>
    </HierarhicalDataTemplate>
  </TreeView.Resources>
</TreeView>

ParentModel.cs

public class ParentModel {
  public ParentOnlyObj ParentData { get; }
  public ICommand ParentButton { get; }
  public ObservableCollection<ChildModel> Children { get; }
}

ChildModel.cs

public class ChildModel {
  public ChildOnlyObj ChildData { get; }
  public ICommand ChildButton { get; }
  public ObservableCollection<ChildModel> Children { get; }
}

With my attempt, I am getting:

> {Name} {ParentButton}
 > ParentData.Text (?? how to add)
 > {Name} {ChildButton}
  > ChildData.Text (?? how to add)
> {Name} {ParentButton}
 > ParentData.Text (?? how to add)

If the Models contains two ParentModel where the first contains one child.

That makes sense since I have not specified where Text is in the XAML. It's just that I'm confused on how to do that.

I am trying to have a TreeView items based on two models, but those two models must change the item's header as well as content, where the content may include further ChildModel.