Workaround: use the following custom editor: using System; using Telerik.WinControls.UI; namespace radGridView_MultipleFilters { public class CustomRadMultiColumnComboBoxElement : RadMultiColumnComboBoxElement { protected override Type ThemeEffectiveType { get { return typeof(RadMultiColumnComboBoxElement); } } public GridViewDataColumn DisplayColumn { get { string displayMember = this.DisplayMember; if (string.IsNullOrEmpty(displayMember)) { for (int i = 0; i < this.MultiColumnPopupForm.EditorControl.Columns.Count; i++) { if (this.MultiColumnPopupForm.EditorControl.Columns[i].DataType == typeof(string)) { displayMember = this.MultiColumnPopupForm.EditorControl.Columns[i].FieldName; break; } } if (this.MultiColumnPopupForm.EditorControl.Columns.Count > 0 && string.IsNullOrEmpty(displayMember)) { displayMember = this.MultiColumnPopupForm.EditorControl.Columns[0].FieldName; } } DisplayMember = displayMember; GridViewDataColumn[] columns = this.MultiColumnPopupForm.EditorControl.Columns.GetColumnByFieldName(displayMember); if (columns.Length > 0) { return columns[0]; } return null; } } protected override object FindItemExact(string text) { int index = this.FindItemIndexExact(text); if (index != -1) { return this.EditorControl.ChildRows[index]; } return null; } protected override void SetActiveItem(string text) { int rowIndex = this.FindItemIndexExact(text); if (rowIndex != -1) { this.EditorControl.CurrentRow = this.EditorControl.ChildRows[rowIndex]; this.Select(this.Text.Length, 0); } } protected override int FindItemIndexExact(string text) { GridViewRowInfo rowInfo = this.FindItemExact(text, this.DisplayColumn.Name); if (rowInfo != null) { return rowInfo.Index; } return -1; } protected override GridViewRowInfo FindItemExact(string text, string field) { GridViewDataColumn[] foundColumns = this.EditorControl.Columns.GetColumnByFieldName(field); if (foundColumns.Length > 0) { for (int i = 0; i < this.EditorControl.ChildRows.Count; i++) { object element = this.EditorControl.ChildRows[i].Cells[foundColumns[0].Name].Value; string elementText = Convert.ToString(element); if (!string.IsNullOrEmpty(elementText) && elementText.Equals(text, this.EditorControl.MasterTemplate.CaseSensitive ? StringComparison.InvariantCulture : StringComparison.InvariantCultureIgnoreCase)) { return this.EditorControl.ChildRows[i]; } } } return null; } } }