Please see the following sample code on how to (page) filter to “Nov” month for your reference:
Workbook unapproved1 = new Workbook("f:\\files\\Test Sheet.xlsx");
Worksheet uapprovedSheet = unapproved1.getWorksheets().get("PIVOT");
PivotTable original = uapprovedSheet.getPivotTables().get(0);
PivotField colFieldofunapprovedSheet = original.getColumnFields().get(0);
//set filter to Nov month.
Regarding sorting column field’s week value in ascending order, I even could not accomplish the task in MS Excel manually. It looks like your week values are mixed and some of the values are not in proper format, that’s why we cannot apply sort order upon it via MS Excel or Aspose.Cells. Even opening your desired file into MS Excel does not show ascending order properly. If you still think it is an issue with Aspose.Cells, kindly do share your expected file with your desired sort order, we will check it soon.