I want to sort a page group based on a property value.Can anyone suggest a way..Thanks in advance
The PDN article is correct in that you cannot sort a Page Group. A Page Group is a Map.
If you allow the sorted list to be updated, for example in a editable Repeating Layout**, as shown in the article you would need to use the Property Reference approach.
If, however, you only need to display the sorted result read-only, you could use a Data Transform to (1) remove every element from a temporary PageList, (2) copy every PageGroup page to that temporary Page-List, (3) Sort the temporary PageList,
** Adding/removing rows with an editable Repeating Grid should not be allowed when sourced to a Property-Reference-based PageList