This feature is designed to extend the Variables window in the SSIS package designer. Currently the extension:
Select the variables you wish to move or copy then click the button. You get the following popup that allow you to choose the new scope for those variables:
The move or copy is executed. Then the package is revalidated and the Error List window is updated with any validation errors. For instance, if a task or expression was referring to that variable in the old scope, the package will not validate any more, and you will need to identify the problem and make the appropriate edits in the package designer to fix the problem.
Select a variable in the variables window, and then click the Find Variable References button to show the references dialog with all uses of the variable shown in a package explorer style dialog.
The Find Unused Variables feature will display a dialog listing any variables that are not used in the package, You can then select one or more variables and remove them.
Similar functionality is available for package parameters, see Parameter Window Extensions.