Thank you for posting! It is not currently possible to configure which test cases should be included in these reports just based on their inclusion of a particular test run. That said, it is possible to limit the cases that are included in these reports by changing the settings in the report options.
With the ‘Comparison for Cases’ report, you can choose to include only the cases from selected sections on the ‘Sections & Test Runs’ tab. On the ‘Test Cases’ tab, you can set a filter to determine which test cases are included. You can also use a combination of both of these settings if this is needed.
With the ‘Comparison for References’ report, cases are included based on the References that are specified. On the ‘References’ tab, you can include the test cases associated with all references found in the suite or you can specify a list of references and this would include any test cases with those references linked in the report. You can also choose to include only the cases from selected sections on the ‘Sections & Test Runs’ tab.
I hope this helps!