Grouping tasks and keep subtasks subordinated / idented

[lgaertner]

Hello,

is it somehow possible to group the tasks within a project and keep the subtasks idented to their parent task?

I understand, that I could change the grouping to parent.<fieldToGroup>, but then the parent tasks are categorized under "no value".

Would it be possible to create a conditional grouping using text mode? 

Something like

IF ISBLANK(parent.<fieldToGroup>) GROUP BY <fieldToGroup> ELSE GROUP BY parent.<fieldToGroup>

Thanks in advance.

Regards

Lars