Relating child line items of same parent

Hi people of powerbi community - i'm fairly new to the power query as a whole and i haven't been able to wrap my head around the below problem:

I have a report coming out from a system that shows a 'Process' - 'Sub-Process' - 'Owner of Process' - 'Reviewers of Process' as shown below in a dummy table. 

I want to be able to provide 'reviewers' with a 'Pivot table' (they dont have BI licenses) that shows them the Items they have to review & the other reviewers they have to work with (Note owners are default reviewers). Currently the pivot table i export to excel cannot display reviewer > Process > Sub-item > other reviewers because they are not related as line items (my understanding).

Is there a way to 'flip' the relation so that each reviewer has a line item with the other reviewers to make the pivot table work -- something like this:

I've tried playing around with pivots, indexing, merging, appending, custom columns but i just can see the way to of getting to my desired pivot table output using power query - but if im missing something much easier i welcome the alternative.

Thanks in advance.