These are currently 2 completely separate database files? Do you want to keep it that way? You could either combine the tables into one file or you can link the files (go to Manage > External Data Sources...)
I'm guessing every project has any number of purchase orders, and every purchase order as 1 and only 1 project.
In this case, you should have a field in purchase orders in which you put the project record id. Then you can link these fields on the relationship graph. If these are separate files, you should probably add them to each others External Data Sources, and then add table occurrences to each others relationship graphs.
Now on your project layout you could put a portal to the purchase orders table, to view a list of related purchase orders.
By the way, you have posted in the Community Feedback area and most people will not see your post. It may be moved eventually. Next time post in the regular forum.
Thank you for your post!
As beverly suggested, I'm going to move this thread from the FileMaker Community Feedback Space (which is specifically for input on the Community itself) to the Discussions Space where you should receive more views and potentially more feedback on this topic!
Ideally, projects and purchase orders should logically be in one database.
Why are they in separate FMP12 files?
Logic doesn't help if the size of the tables are staggering!
I have a solution with 1 interface and 4 "data" files (many tables in each). These are "logically" separated for lots of reasons, but mostly the number of records and having to backup ONE db/file or 5 (some only get backed up daily, others hourly).
And sometimes there is separation of data because of access levels on that data. Admin can see what's behind door #1, but the janitor cannot. However anyone (internal network) can see what's behind door #3. And door #2 is open as read only to anyone (even the world). It's far easier to set privileges "logically grouped this way.
Gotcha. Makes sense. Very unusual situation in my experience.