Hi Virat,
In %OnGetFilterMembers, you will have access to pFilter, which will contain the name of your filter, "SubjectName" in this example. You will also have access to pMembers, which is an array of members that the SearchBox dropdown will use in the UI. By default, this will contain the results from sql="SELECT DISTINCT SubjectName FROM BI.Invoice". You will also have access to pFilterValues, which contains an array of already selected values. In your case, "Virat and Big Show". You would then need to use this information to remove values from the pMembers array to reduce the available members.
By default, IRIS BI does this "member filtering" for you. The use of KPIs is very customized, so it requires some additional custom logic to allow this behavior
What are you trying to modify inside of %DeepSee.Dashboard.Utils?
It turns out this was a bug with parallel processing where the negative numbers in the data were more negative than the null marker caused data to be skipped. Development is fixing this