Unfortunately, the original FPS/RTI reports cannot be retrieved, as they are only created when the file is first generated and gets overwritten with every subsequent file generation.
However, you may be able to create an Insight Report using the RTI History (Pay) table to view the data if you have the relevant permissions. Alternatively, your Insights Super User may be able to do this for you.
Log onto Core Portal.
In the top left, use the Dashboards drop-down and select Insight.
In the top right, use the Actions drop-down and select Create Report.
Enter the report name then click OK.
Click Add then select Column.
In Filter Columns by view section, enter RTI History (Pay).
Select required fields.
If required, filter by the Pay_Group, Payroll_Period.
Click Run report.