How do I create a treeView for a List<List<int>?

I have a EntityDisplay class that contains 2 properties:

public sealed class EntityDisplayObject
{

    public ICollection Collection { get; private set; }

    public string CollectionName { get; private set; }

    public EntityDisplayObject(ICollection collection)
    {
        this.Collection = collection;

        this.CollectionName = $"{this.Collection.GetType().Name [{this.Collection.Count}]";
    }

}

Sometimes Collection will be a List<int>, but sometimes it will be a List<List<int>.

I currently have it working for List, but can not find a way to do it for nested lists.

This is my xaml at the moment:

<Grid x:Uid="Grid_4">

    <TreeView x:Uid="TreeView_2"
              Background="Transparent"
              BorderThickness="0"
              Padding="0">

        <TreeViewItem x:Uid="TreeViewItem_1"
                      Header="{Binding CollectionName}">

            <ListBox x:Uid="ListBox_2" MouseDoubleClick="TreeViewItem_MouseDoubleClick"
                     ItemsSource="{Binding Collection}"
                     Background="Transparent"
                     BorderThickness="0">
            </ListBox>

        </TreeViewItem>

    </TreeView>
</Grid>

Simple list working with the xaml

For nested lists, I get the tree view header and expandable option, but instead of showing me the list as the first screenshot, it gives me (Collection). Nested list currently

Solution

Thanks everyone for the help. At the end, this code did the job. What I had to do is for each collection, get the items and put them inside a new List property, and if any of the items are also collections, do the same to them which will give each object a List of children (if they are a collection).

foreach (var child in collection)
{
    if (child is ICollection childCollection && childCollection.Count > 0)
{
    var childObject = new EntityDisplayObject(childCollection);
    this.ChildCollection.Add(childObject);
}

And this is how the xaml looks like to be able to display something like this

Item 1
  -Item 2
    -Item 3
    -Item 4
    -Item 5
      -Item 6
  -Item 7

<TreeView x:Uid="TreeView_2"
          Background="Transparent"
          BorderThickness="0"
          Padding="0"
          ScrollViewer.HorizontalScrollBarVisibility="Disabled">

    <TreeViewItem x:Uid="TreeViewItem_1"
                  Header="{Binding CollectionName}">

        <ItemsControl ItemsSource="{Binding ChildCollection}"
                      ItemTemplateSelector="{StaticResource EntityInspectorDataTemplateSelector}"
                      Background="Transparent"
                      BorderThickness="0">
            
        </ItemsControl>

    </TreeViewItem>

</TreeView>