I am currently calculating the contribution for my dataset and have already sorted my values in descending order using the rank tile with date and group for my partitions.
What I'm hoping to do is sum the previous value + the following value until my last value would be the grand total.
In theory, I thought using the rank & window tile would be ideal, but the issue arises in the first value. If you notice in the table, it calculated the first value of the partition twice.
Setting the preceding to unbounded and following to 1, I was able to achieve the results I wanted but with one teeny tiny issue: those first values.
Do you have any suggestions? I'm so close, yet so far.