As check the sample on xamComboEditor in xamGrid, it is a little complicated:

<ig:TemplateColumn.EditorTemplate>
    <DataTemplate>
        <ig:XamComboEditor x:Name="CategoryEditList" Loaded="CategoryEditList_Loaded"
    ItemsSource="{StaticResource categoryProvider}"
    SelectedItem="{Binding Category,
    Mode=TwoWay,
    Converter={StaticResource categoryConverter},
    ConverterParameter={StaticResource categoryProvider}}"                 
    DisplayMemberPath="Value" />
    </DataTemplate>
</ig:TemplateColumn.EditorTemplate>
It uses converter with parameter and assume data source for itemSource from StaticeSource.

My case is like this:

Data coming from View Model:

For xamGrid ItemSource:

  private IList<Department> _myDepartments;
        public IList<MyDepartment> myDepartments
        {
            get { return _myDepartments; }
            set
            {
                if (this._myDepartments != value)
                {
                    this._myDepartments = value;
                    RaisePropertyChanged("myDepartments");
                }
            }
        }

  private IList<Department> _allDepartments;
        public IList<MyDepartment> AllDepartments
        {
            get { return _allDepartments; }
            set
            {
                if (this._allDepartments != value)
                {
                    this._allDepartments = value;
                    RaisePropertyChanged("AllDepartments");
                }
            }
        }

I want to xamComboEditor can be set in xaml like:

<ig:TemplateColumn.EditorTemplate>
<DataTemplate>   
<ig:XamComboEditor
    SelectedItem="{Binding Department, Mode=TwoWay}"  
    DisplayMemberPath="DeptName"
    ItemsSource="{Binding AllDepartments}" />
</DataTemplate>
</ig:TemplateColumn.EditorTemplate>

But it is obviously above binding not working.

How to implement with this situation?