Alternate Watch Views
The Watches Window has alternate watch list views which work similarly to having tabbed watches. With alternate views, you can collect specific watches in groups and when you click on a watch view diamond, only the variables associated with that view will be displayed. Select that diamond again and it will default to the standard view. This feature works like a filter.
You enable this feature by going to Tools>Options>Embedded>Generic Settings. The default is to have one watch window.