Thanks very much for posting the PBIX file. Being able to dig into the details of your data model was essential in getting to the solution.
The problem with your model was twofold. Power BI is optimized for a star schema data model - single level dimension tables connected to fact tables via unidirectional, one-to-many relationships. Your data model didn’t meet either of these conditions. To conform it to a standard star schema, I collapsed the branch, region, old division and new division tables into a single dimension table (called Organization), removed the duplicates and created a one-to-many relationship with the Forms table. Here’s the old data model structure versus the new.
With these changes, the slicers now synch correctly and filter the fact table properly.
I hope this is helpful. Full solution file posted below.
If you’re interested, below is an excellent article that explains in detail why you should always strive to build your data model as a star schema:
P.S. your data was a bit “dirty” - duplicate names for the same regions and branches, some missing data, inconsistent coding, etc. I cleaned it up in order to make the relationships work properly, but you will need to check it and likely change it, since I just guessed in some cases at the correct name/code.
eDNA Forum - Region Branch Structure Solution.pbix (287.8 KB)