protected void Grid_ProcessColumnAutoFilter(object sender, ASPxGridViewAutoFilterEventArgs e) { if (e.Column.FieldName == "Numbers") { switch (e.Kind) { case GridViewAutoFilterEventKind.CreateCriteria: CriteriaOperator co = CriteriaOperator.Parse(Grid.FilterExpression); if (co is GroupOperator) { GroupOperator go = co as GroupOperator; CriteriaOperator operand = go.Operands.Find(op => op.LegacyToString().Contains("MyNewFunction")); if (operand is CriteriaOperator) { go.Operands.Remove(operand); } Grid.FilterExpression = go.LegacyToString(); } else if (co is CriteriaOperator) { string filter = co.LegacyToString(); if (filter.Contains("MyNewFunction")) { Grid.FilterExpression = string.Empty; } } if (e.Value.Contains('-')) { CriteriaOperator cop = new FunctionOperator(FunctionOperatorType.Custom, "MyNewFunction", e.Value, new OperandProperty("Numbers")); e.Criteria = cop; } break; case GridViewAutoFilterEventKind.ExtractDisplayText: default: break; } } }