Check the samples, to see the basic tasks: https://docs.abp.io/en/commercial/latest/samples/index
The exact solution to your question may have been answered before, please use the search on the homepage.
If you're creating a bug/problem report, please include followings:
ABP Framework version: v4.4.4
UI type: MVC
DB provider: EF Core
Tiered (MVC) or Identity Server Separated (Angular): no
[ ] Exception message and stack trace: Required Search Functionality in Organization Unit > Roles at a time of add role as per link attachment.Search Issue