Hello - I'm trying to utilize the Multi-row formula to solve my problem, but I don't know that it will get me there. Any alternative suggestions I'm open to! Essentially trying to combine the values from two separate columns across multiple rows of data, if certain criteria are met. A basic example is shown below. For each row in a sequence, I need to combine the value of [Row1: Weekend Hours] + [Row+1: Lag Hours] and place the new value in the "Total Time Less Weekends" column. Sometimes there may be a null value in either column, the same calculation should apply.

Another caveat is for each row 1-7 above, the data is assigned to one Document. My data set has thousands of documents, each with anywhere from 4 - 20+ rows. The first row (logid) of each document should have a Lag Hours value of 0, so the formula I have that is returning the error looks like the following....
iif([logid]='00001', [Lag_hrs], ([Lag_hrs]+[Row-1:Weekend Hours]),'hour')
This may be confusing, so happy to provide more details where needed!