Как забиндить компаненты в DataGrid?

Есть такой DataGrid

<DataGrid Grid.Row="1" x:Name="DGStudents" Margin="10" IsReadOnly="True" 
              AutoGenerateColumns="False" ItemsSource="{Binding Path=studends}">
        
        <DataGrid.Columns>
            <DataGridTextColumn Header="Студент" Width="*" Binding="{Binding Path=FullName}"/>
            <DataGridTextColumn Header="Группа" Width="*" Binding="{Binding Path=Group}"/>
            <DataGridTextColumn Header="Курс" Width="*" Binding="{Binding Path=Course}"/>
        </DataGrid.Columns>
        
        <DataGrid.RowDetailsTemplate>
            <DataTemplate>
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="0.25*"/>
                        <ColumnDefinition Width="0.75*"/>
                    </Grid.ColumnDefinitions>

                    <ComboBox Grid.Column="0" ItemsSource="{Binding Path=Exams}"
                              DisplayMemberPath="Name" IsEnabled="True">
                    </ComboBox>
                    <Grid Grid.Column="1">
                        <Grid.DataContext>
                            <view:OrganaizerManagerVeiwModel/>
                        </Grid.DataContext>
                        <TextBlock Text="{Binding Path=Description_of_student}"/>
                    </Grid>
                </Grid>
            </DataTemplate>
        </DataGrid.RowDetailsTemplate>
    </DataGrid>

Классы для биндинга

internal class Student: PropertyChanging
{
    public string FullName { get; set; }
    public string Group { get; set; }
    public int Course { get; set; }
    public List<Exam> Exams { get; set; }
    public Student(string fullname, string group, int course)
    {
        FullName = fullname;
        Group = group;
        Course = course;
    }
}

internal class Exam
{
    public string Name { get; set; }
    public string Description { get; set; }

    public Exam(string name, string decr)
    {
        Name = name;
        Description = decr;
    }
    public override string ToString()
    {
        return Description;
    }
}

Коллекция, которая забиндена к DataGrid

 public ObservableCollection<Student> studends { get; set; }
        = new ObservableCollection<Student>()
            {
                new Student("Ivan Petrov", "21-KB-PR2", 2) 
                    {Exams = new List<Exam>()
                        { 
                        new Exam("Math", "Perfect"),
                        new Exam("OOP", "Good"),
                        new Exam("TRPO", "Bad")
                    }
            }
        };

Вопрос. Как можно забиндить два свойства SelectedItem и Description_of_student Сами свойства:

private Exam _selected_item;

    public Exam SelectedItem
    {
        get => _selected_item;
        set { Set(ref _selected_item, value);
            MessageBox.Show(_selected_item.ToString()); }
    }


    private string description_of_student;

    public string Descruption_of_student
    {
        get => description_of_student;
        set => Set(ref description_of_student, value);
    }

При попытке забиндить через Path у меня отображаются свойства класса Student