Updating of balance when a condition is met

[Chinarv1989]

Thanks in advance on any help on how to achieve the output column as described below.

Have a balance sheet dataset with the contract balance at the end of each month. The balance is zero for some months (such as Jun/Jul21).

To the above data, need to join the below data between the date range such that the new balance is added to the previous balance.  

Subsequently, if in any given month, the value in the field 'Balance 1' is zero (as is the case in Jun/Jul21), the corresponding value is extracted from the date range that month belongs to (i.e the value in the field 'balance from other dataset' is replace by the value from the date range). Also included is the excel with the working should it be difficult to understand the problem. 

[martinding · Accepted solution]

Hi @Chinarv1989 ,

Please see my attached workflow.

[Chinarv1989]

Brilliant and ohh so elegant solution...!! Thank you very much!