Multi level parent child hierarchy summarization

In a hierarchical table "BaseData" , I have to summarise an attribute "timespent" for all LEVELS of child work item. the problem is that the parent (where it need to be summarize) could also be a child of another workitem ( this is where Pathcontains might fail - dont suggest that please.)
The table is fully flattend table going upto 9 levels.

I have follwoing columns 

Workitem
Workitemtype ("Program Epic", SWApproval, Defect, Story, Work and Review, Task)
Path ( this is generated using DAX path function)
Level1
Level2
level 3 ..... Upto level 10. ( each level will be represented as an idependent workitem )
TimeSpent ( this is what i need to summarize)

Some Cases - Program EPIC-> Defect-> Story -> Task
OR
Defect-> Story->Work& Review-> Task
OR
Program Epic -> Program Epic -> Defect -> Story-> Task
OR
Program EPIC-> SWApproval-> Story -> Task

I want only the sum of child ( All levels) for a workitem type "SWApproval" going recursively in the table or using the flattened hierarchy.

The SWApproval could appear at any level and have children (grand children) workitems. 

Here is sample data.