procedure TForm1.Button3Click(Sender: TObject);
var
BufDataset2: TBufDataset;
begin
BufDataset2 := TBufDataset.Create(nil);
BufDataset2.FieldDefs.Add('FieldName WithSpace', ftString, 200);
BufDataset2.CreateDataset;
BufDataset2.AppendRecord(['Value1']);
BufDataset2.AppendRecord(['Value2']);
BufDataset2.Filter := 'FieldName WithSpace = ''Value1''';
//BufDataset2.Filter := '[FieldName WithSpace] = ''Value1''';
BufDataset2.Filtered := True;
end;