For package-based drill-through, if there is only one target report, you click on the Go To link in the right-click menu to go directly to the target report (not Related Links that you see when you hover your mouse over the Go To menu). If there is more than one target report, clicking on Go To has the same effect as clicking on Related Links. In both cases, you see the Go To page, which allows you to select the target report that you want.
For more information, see Drill Through to Another Target.