partial dril down on charts

Hi all !

What would be the best way to achieve this kind of figure ? 

In table and matrix, you can easily split a part of the hierarchy to drill down in the dimention you want to explore. I would like to do it also in graphs like chart bar or lines. Is this an easy way to do it ? (I'm pretty sure there are a Python or a R way, but I'm not good with those laguages)  Or a custom visual my be ?

I tried with the group system. Unfortunately, on time data, the system wants to group everything the same way and all the bins have to be the same lenght :-/

thanx in advance

Fred