Two Regions in same app for same company. Regions do same work but do not want to see or share data.

Definitely do not duplicate your app!  Quick Base access control is stellar and flexible and bullet proof.

if you only will have a couple of Regions, I would setup a Role for each Region  and though the Custom Role Permissions limit access to only view the appropriate Region.  Note that you probably have some kind of hierarchical structure with region being at the top, and you can lookup the region to any child records and also limit access to any Child records too - like Projects for a Region and tasks for projects for a Region and tasks

Here is some help on Roles

https://help.quickbase.com/user-assistance/cs/cs_about_roles.html
 

I'll try it. Thanks for the fast response. You are all over this site (thank goodness), there's many of us who need help. Appreciate it.

I followed these steps and appears to work, but wanted a quick double-check in case I forgot something.
1. App has to be setup so that the top-most Parent is a Table with just the Regions. This Parent has one to many relationship to numerous Child Tables.
2. Setup a Role for each of the two Regions and a role for the manager who accesses all.
3. Permissions for the regional roles - Create a Custom Rule for Each Table to restrict access to REGION = East or Region = West. I must create the custom rule at each table if I want all data to be separated by Region for this role.
Permissions for the Manager: No custom rule, can View, Can Modify all tables.
4. The View, Edits, Add, Delete, Reporting for the Regional roles will be separated for the user automatically base on the Regional role they are assigned
Thanks!

Yes. That sounds right.