Tasks view lets breakdown tasks into multiple subtask levels which can be easily expanded or collapsed to show required records.
However, if you need to create a report, pivot table or chart on particular subtask level, you cannot set appropriate filter, because there is no default property for that purpose. You need to create a custom property that will define your work breakdown structure, and then set filter by the given property.
For example, you have 4-level WBS (process/phase/task/subtask) and want to generate various reports on particular levels.
Report “List of tasks”
Report “List of phases”
To set filter by particular subtask level