Fill UP Or Fill DOWN Based on Condition|Power Query|Excel Forum|My Online Training Hub

Calling Power Query Genesiuses - Looking to the masterful minds to solve this one. 

Objective: Compare Data Set 1 amount to Data Set 2 amount based on ID Number

Goal is to compare the amounts/counts based on the ID Number in both data sets and issue expense for differences. 

Details:

I want to compare amounts over a given timeframe (in this case FEB) based on the ID Number. 

There are ID Numbers that have blanks in some of the rows for the provided data.

I was originally attempting to use “Filled Down” but there are times in the data set where the ID Number should be "FIlled Up" and also times where it should remain blank (null). 

Please see attached.

Can you please work your magic to provide a PowerQuery solution?

Also, is there perhaps a better alternative for comparing this type of data set?