Directory view grouping gives you the ability to group similar files in directory comparison by relative path, type, and status.
This feature can be accessed in two different ways: through the View menu using View | Grouping and through the right-click context menu under Grouping.
When sorting by column with listview grouping enabled, the files will be sorted within each group, unless the sorting is the same as the grouping type. For example, if listview grouping is enabled with grouping by type and the Type column is sorted top to bottom, then the groups themselves will be sorted alphabetically from A to Z.
Another feature of listview grouping is Collapse All and Expand All which can by accessed from the View menu via View | Grouping | Collapse All or from the right-click context menu. Collapse All simply hides all files under their respective groups and Expand All does the opposite.
Also, when certain groups are collapsed and expanded, the states of each group will persist even when the directories are re-compared. Another useful feature of listview grouping is that when a group heading is clicked, all files underneath it will be selected, allowing for easy control of groups of files.