private ListCollectionView _departmentNotes;
public ListCollectionView DepartmentNotes
{
    get
    {
        if (_departmentNotes == null)
        {
            _departmentNotes = new ListCollectionView(AllScenesAndPartials);
        }
        return _departmentNotes;
    }
    set
    {
        _departmentNotes = value; RaisePropertyChanged();
    }
}

public ObservableCollection<Scene> AllScenesAndPartials { get; set;}

<Grid>
  <TextBox Text="{Binding DepartmentNotes/Camera, UpdateSourceTrigger=PropertyChanged}" />
</Grid>

<UserControl.Resources>
    <DataTemplate x:Key="CameraTemplate">
    <StackPanel>
        <Expander  Grid.Column="0" Grid.Row="0" Header="Camera">
            <Grid>
                <TextBox Text="{Binding DepartmentNotes/Camera, UpdateSourceTrigger=PropertyChanged}" /> ////----->Trying to make this binding work!
            </Grid>
        </Expander>
    </StackPanel>
</DataTemplate>

<local:NotesTemplateSelector CameraTemplate="{StaticResource GripElectricTemplate}" x:Key="NotesTemplateSelector"/>

</UserControl.Resources>

<Grid>
    <ListBox x:Name="Notes" ItemsSource="{Binding NoteHeaders}" ItemTemplateSelector="{StaticResource NotesTemplateSelector}">
</Grid>