[c#]
private void InitGrid(FlyGrid grid)
{
  //connect to ColumnFilterValidate event
  grid.ColumnFilterValidate += new ColumnFilterListValidateHandler(ColumnFilterValidate);
}

//Apply our own filters list to the Order Date column.
private void ColumnFilterValidate(object sender, Column column, ArrayList filterList)
{
  if (column.Caption == \"Order Date\")
  {
    filterList.Clear();
    DateTime end93 = new DateTime(1993, 12, 31);
    DateTime end94 = new DateTime(1994, 12, 31);
    DateTime end95 = new DateTime(1995, 12, 31);
    DateTime end96 = new DateTime(1996, 12, 31);
    FilterItem[] in94Year= new FilterItem[] {
          new FilterItem(end93.ToShortDateString(), FilterOperator.And, ConditionOperator.GreaterThan),
          new FilterItem(end94.ToShortDateString(), FilterOperator.And, ConditionOperator.LessThanOrEqual)
      };
    FilterItem[] in95Year= new FilterItem[] {
          new FilterItem(end94.ToShortDateString(), FilterOperator.And, ConditionOperator.GreaterThan),
          new FilterItem(end95.ToShortDateString(), FilterOperator.And, ConditionOperator.LessThanOrEqual)
      };
    FilterItem[] in96Year= new FilterItem[] {
          new FilterItem(end95.ToShortDateString(), FilterOperator.And, ConditionOperator.GreaterThan),
          new FilterItem(end96.ToShortDateString(), FilterOperator.And, ConditionOperator.LessThanOrEqual)
      };
    filterList.Add(new FilterHelper(\"[All]\", FilterMode.All));
    filterList.Add(new FilterHelper(\"[Custom]\", FilterMode.Custom));
    filterList.Add(new FilterHelper(\"Only 1994 year\", in94Year));
    filterList.Add(new FilterHelper(\"Only 1995 year\", in95Year));
    filterList.Add(new FilterHelper(\"Only 1996 year\", in96Year));
  }
}

[c#]
private void InitGrid(FlyGrid grid)
{
  //connect to ColumnFilterValidate event
  grid.ColumnFilterValidate += new ColumnFilterListValidateHandler(ColumnFilterValidate);
}

private void ColumnFilterValidate(object sender, Column column, ArrayList filterList)
{
  if (column.Caption == \"Order Date\")
  {    
    filterList.Clear();
    DateTime end93 = new DateTime(1993, 12, 31);
    DateTime end94 = new DateTime(1994, 12, 31);
    DateTime end95 = new DateTime(1995, 12, 31);
    DateTime end96 = new DateTime(1996, 12, 31);
    CultureInfo ivCulture = CultureInfo.InvariantCulture;
    FilterItem[] in94Year= new FilterItem[] {
      new FilterItem(end93.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.GreaterThan),
      new FilterItem(end94.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.LessThanOrEqual)
    };
    FilterItem[] in95Year= new FilterItem[] {
      new FilterItem(end94.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.GreaterThan),
      new FilterItem(end95.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.LessThanOrEqual)
    };
    FilterItem[] in96Year= new FilterItem[] {
      new FilterItem(end95.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.GreaterThan),
      new FilterItem(end96.ToString(ivCulture.DateTimeFormat.ShortDatePattern, ivCulture), FilterOperator.And, ConditionOperator.LessThanOrEqual)
    };
    filterList.Add(new FilterHelper(\"[All]\", FilterMode.All));
    filterList.Add(new FilterHelper(\"[Custom]\", FilterMode.Custom));
    filterList.Add(new FilterHelper(\"Only 1994 year\", in94Year));
    filterList.Add(new FilterHelper(\"Only 1995 year\", in95Year));
    filterList.Add(new FilterHelper(\"Only 1996 year\", in96Year));
  }
}

[c#]
public class CustomFilterColumn : Column
{
  public CustomFilterColumn(string caption) : base(caption){}
  protected override object[] GetFilterList(FlyGridViewPort port)
  {
    ArrayList filterList = new ArrayList(base.GetFilterList (port));
    bool blanksRemoved = false, nonBlanksRemoved =  false;
    for(int i=0; i < filterList.Count; i++)
    {
      FilterHelper fh = filterList[i] as FilterHelper;
      if (fh != null && fh.Value is FilterMode)
      {
        FilterMode mode = (FilterMode)fh.Value;
        if (mode == FilterMode.Blanks)
        {
          filterList.RemoveAt(i);
          blanksRemoved = true;
          i--;
        }
        else if (mode == FilterMode.NonBlanks)
        {
          filterList.RemoveAt(i);
          nonBlanksRemoved = true;
          i--;
        }
        //stop when both option removed
        if (blanksRemoved && nonBlanksRemoved)
          break;
      }
    }
    return filterList.ToArray();
  }
}