Partition of data by a condition & Selectively changing the values of a column

[Nidhin123]

Thanks Ivan.I have solved half of that problem myself and reworded the pending questions.You can see that here

Selecting the top value after sorting

Hi Guys, I am sorting a column in descending order and I need to use the first value of the sorted row as a condition in the Rule engine node.I am sorting the data by a column Month1 using sorter and I need to check each values of other column Month2 if it is less than the top value of Month1.Could you please let me know how to do this. Hypothetically the expression in my rule engine should be $Month$ < $Current_Month$[1] =>$Month$ But not sure how to find Current_Month$[1]