Scope
Scope is specific to drill-through definitions
created using Drill-through Definitions in IBM® Cognos® Connection
(package drill-through definitions). The scope you set defines when
the target report is shown to the users, based on the items they have
in the source report.
Usually, you define the scope of a drill-through path to match a parameter that it passes. For example, if a target report contains a list of employees, typically you want to display the report as an available drill-through choice only when a user is viewing employee names in a source report. If employee names are not in the source report and the scope was set on the employee name in the drill-through definition, the employee report does not appear on the list of available drill-through target reports in the Go To page. You can set the scope to a measure or to an item in the report.
In report-based drill-through access, where the drill-through path is associated with a specific report column, the column serves as the scope.