Hi Sreenu,
Please confirm that we are talking about "Approve Purchase Orders" app, right?
Runtime Process:
+ When PO is created, workflow is triggered based on your MM release strategy configuration.
+ Approver is assigned based on the release strategy.
+ Workflow engine delivers workitems to the approver's inbox. It is SBWP.
+ Fiori "Approve Purchase Orders" app reads workitems from SBWP filtered by task ID and displays PO.
So if there is no workitems in the logon user's SBWP, Fiori app does not show any PO.
You can look at workflow log in the transaction SWI2_FREQ and you can find how many workflow instances are created and who is an approver.
Regards,
Masa / SAP Technology RIG