Hi @BrianJ,
Thanks for your reply and your efforts 
(But 
) it is weird because you placed a “Company” slicer on top of another duplicate of “Company” slicer. Then I noticed you only filtered with 1 company:
Again if you keep just one company filtered it works fine (thank you ) but if you filter with multiple companies there’s still the issue. It will find the previous row but not from the same company and the [PQIndex] seems not to be useful at the end… tricky tricky ?! 
I guess data would rather be transformed in PQ, DAX seems complicated in this context…
Thanks again 
Best,
Alexandre