Filtering the task outline
You can create filters that cause the project to show only tasks which meet certain criteria. So you could, for instance, just look at tasks that were completed in the past week, or tasks whose variance is greater than three days.
Choose Filter Tasks from the View menu, or click the equivalent button in the toolbar. A sheet appears for setting up your filtering criteria. You can add as many criteria as you like, and indicate whether to include tasks which match all of the criteria or any of them.
Any tasks which match your criteria (and the groups they belong to) remain in the outline, while the rest of the project is hidden away. You can work with the project normally while it is filtered, but you can only edit the visible tasks. The hidden tasks are hidden in every view: the task outline, the Gantt chart, and the resource timeline.
If you export or print a project while a filter is on, only the visible tasks are included in the exported file.
When you're done, choose Remove Filter from the View menu or click the toolbar button again; all of your tasks reappear, no worse for the wear.