Matrix visual tooltip to show values

[GrayGunn5]

I have a table of elements such as:

Each person can have multiple categories. From this table I have managed to create a matrix like this:

In order to achieve this (with help from this forum) I used the following Measure to aggregate the numbers:

Measure = if(VALUES(Classification[Classification])=VALUES(Classification_dup[Classification]),0,CALCULATE([People],CALCULATETABLE(SUMMARIZE(VALUES(Data[IdPerson]),Data[IdPerson]),ALL(Classification),USERELATIONSHIP(Data[Classification],Classification_dup[Classification]))))

I am now struggling with trying to create a tooltip that shows the Name (or ID) of the people in each cell, i.e. I want to create something that liiks like this:

The mock up file is attached below:

https://www.dropbox.com/s/i2wrw6zowwjzxs0/Cross%20matrix%20example%20post.pbix?dl=0 

I would be very grateful for any help.

[AlexisOlson · Accepted solution]

Try a CONCATENATEX iterator over your CALCULATETABLE (instead of using it as a filter) for the measure to use in the tooltip.

CONCATENATEX ( _SharedIds, "ID: " & Data[IdPerson] & UNICHAR ( 10 ) )

See attached.