Filtering a Business Unit table with a Slicer that applies on the Hierarchy Path

[fsim]

Hello !

Here is my issue.

I'm working with Business Units from CRM365. BU are in a Hierarchy. I want to create a slicer on the BU that will filter the Bu table not only on the selectedBU but also to all the BU "under" the selected one.

I tried many solutions (pathcontains, containstring etc...). None works. My last successfull attemps is using a measure.

(based on this https://community.powerbi.com/t5/Desktop/Dynamic-filtering-slicing-if-text-contains/m-p/425504/highl...)
Unfortunately I cannot Filter a page using a measure. It needs to be a column.

So I modified it ,  but the Selected BU value is always empty... I'm a little bit stuck here.
In order to get this done. I duplicated my BU table. (one is BU DL and the other one is BU)
Search BU is the result of the measure. Filter Search Bu is the above column.
any idea would be much appreciated.

I also tried the column 

Filter Search BU =     PATHCONTAINS( 'Business Unit (DL)'[Bu Path], [Selected BU]) --> always returns False
and

Filter Search BU =     CONTAINSSTRING( 'Business Unit (DL)'[Bu Path], [Selected BU]) --> always returns True