Hi Tareq,
For Leave request scenario to be working from End to End. ( My Leave request -> Approve Leave requests). If ESS/MSS is in place then well and good. Else, if you just want to run a scenario for a demo user. You can create 2 users.
Employee - > Who will create leave request. (Assign PERNR)
Manager -> Who will approve leave request (Assign PERNR)
Now Employee and Manager should be in same Org structure.
Once created, the solution should work out. You can execute the scenario from PTARQ transaction and approve using the standard leave request approval workflow.
Configure the same workflow for your fiori applications.
Now use the same userids to create leave request using "My Leave requests" and approve using Manager id using " Approve leave requests"
Best regards,
Tejas chouhan