New Post: Custom ItemSource for combobox in wpftoolkit propertygrid

I am trying to add a combox box in propertygrid and the ItemsSource will be received at runtime by reading an xml file.

how to create it. On selection of any item from that combobox, i should fill another combobox itemssource data.

I should be able to get both data in ViewModel. Please help me in resolving it.