There is 2 things that could be done.

1) Create a style in code for the HierarchicalGroupByControl, in which you set the Visibility to Collapsed, then add the Style to the newly created DataGridControl's Resources collection ( set the key as typeof( HierarchicalGroupByControl ) ). This way, the implicit style will only affect the DataGridControl in question.

2) Create a new View instance on which you set the UseDefaultHeadersFooters property to "False", then add a new DataTemplate in its FixedHeaders for the ColumnManagerRow. Assign the View to the DataGridControl and there will be no HierarchicalGroupByControl.