Attached is the solution you asked for, I think. If it's not exactly what you wanted let me know and we can try and work to get a solution for you.
There are two calculated fields that you should take note of:
- Difference Metric
- Show Hide
"Difference Metric" returns the difference between the first and last Metric Value in the partition (in this case the range of months selected).
"Show Hide" gives you control to hide everything except the last month, and so only show a user the difference, while still allowing Tableau to calculate over the partition.
If you have any issues or questions, let me know.
Thanks for the help Kevin! Really appreciate it! That works incredibly well.
No problem Jason, glad I was able to help