I guess you want below output
I have crated 3 simple calculated fields for your easy reference for this and kindly ref attached workbook.
you can take off unwanted columns from above table viz.
let me know if this meets your requirement.
Tableau Forum - Test (1).twbx 38.7 KB
This is close, but what i am looking is the monthly data to role to represent the offices themselves, only articulating whether or not they had files for the year submitted.
For example in 2017, Office C and A both had files submitted during the year. Office B did not. Therefore, I would like the aggregation to show that 1/3 branches did not submit any files for the year. Please let me know if this helps make sense.
Expected Results Main Cluster 2017 33% Main Cluster 2018 33% Main Cluster 2019 100%