Help with PowerQuery to populate the error codes list from coding activity

Hi All,

Hope you are doing well!..Wishing you a happy new year...I am trying to populate the error codes based on the coding activity.. In my Input excel sheet combination if Billid and ctextid indicate the a specific patient visit and the coder indicates the first person who codes the patient visit and then the Auditor is the second person who does the checking of the work done by the coder corrects if it has any mistakes and also adds if any ..So final correct version of the code is the one done by the auditor...The error codes are the ones who are not there in the coder version and are there in the auditor version..Added codes are the ones that are there in the auditor version but are not there in the coder version...Both the added codes and the deleted codes are the error codes for that patient visit (combination of ctextid and billid).. Attached the excel sheet with the input and the needed output tabs..Can you please help me here...

Thanks,
Arun

@AliGW : Sure ...Appreciate your help!..Yes I will update the excel version to my user profile...Sorry yes I accept the output was wrong...Will make sure that I double check them..

@Bo_Ry: Thanks!!..This works...Really appreciate your help!!

@AliGW: Yes your solution works as well!..Sorry for not mentioning that!!...Hope you have a great day!