I was also stuck in same issue.
But data showing by Fiori Apps is not purely filter based on authorization available in backend system.
Backend system having below filter in authorization objects.
Document Type in Purchase Order M_BEST_BSA
Purchasing Group in Purchase Order M_BEST_EKG
Purchasing Organization in Purchase Order M_BEST_EKO
Fiori Apps not checking all authorization objects.
Have different purchasing officer (which are actually purchasing group) who are responsible for different purchasing organization in company.
1. Purchasing group M01 responsible for purchasing org. ABC and XYZ for plant 0001 , 0002, 0003
2. Purchasing group M02 responsible for purchasing org. XYZ for plant 0004
Now user ABC who is purchasing group M01 get login into fiori apps should only get PO based on rules explained above.
Now user DEF who is purchasing group M02 get login into fiori apps should only get PO based on rules explained above.
Please guide how to get desired results.