...
Here issues are displayed in a levelled dependency tree according to issue hierarchy. The hierarchy can be customised on the Issue Hierarchy configuration page. If not configured, the graph will follow the deafult issue hierarchy. In the example below you can see that the default hierarchy has been customised and the ‘Task’ issue type has been granted seniority over the ‘Story’ issue type, while other issue types have regained their default rank.
...
Graph filters
Data displayed in the graph can be filtered by a number of variables:
link types
issue types
JQL query
...