complex pivot table

[GillesB]

Hi
I'm trying to build a complex Pivot (see picture)

Up to now, I created 1 measure per line
I can easily do the month per month + total view, that's pivot basics

But I need help for the 2 semestrial columns and the 2 other columns (Year to date = months before current month & Year to go = Months from current month and after) that I need to pu on the same pivot table

I added sample data added to the post, so if you can help me, I'll be very thankfull 

Thanks a lot