Use slicer to activate a calculation item

Struggling a lot to find an answer, and I'm afraid I'm making it unnecessarily complicated.

My final goal is to achieve something like this, where both the X- and Y-axis can be modified using slicers. Both of them can have more than 4 different values (and will grow in future development).

A bit of context: I count the number of students, and compare how they score in 2 different categories (e.g. the score for a certain subject, their number of abscenses, the amount of homework, etc.). These categories can be chosen on X- or Y-axis to look for possible interactions between the 2 categories (e.g. students who are more days absent from school, have a lower score for math).

These categories have to be measures, it is not possible to store them as calculated columns.

Since I do not want to create a different measure for each possible combination of 2 categories, I thought it was best to use a Calculation Group. There is a Calculation Item for each categorie (e.g. "number of abscences), and by using SELECTEDMEASURE() in each calculation item I can insert any other measure to calculate the number of students with each combination of categories.

My solution so far:

I create a Selector table to be used as a slicer. This selector determines both the chosen measure and the axis categories.

The data model for the X-axis looks like this:

SelectorX: the table I use in the slicer

Measure X-axis: Field parameter to chose the measure to show

Category X: Categories (labels) to be shown on the X-axis (as legend) - also a Field parameter

For the Y-axis, I started a similar approach, but the main difference is that the Measure for the Y-axis, is a Calculation Item. It is not possible to create a relation between SelectorY and the Calculation Group.

I thought to solve it by using a measure in my visual like this:

Measure =
CALCULATE (
   ?????,
   TREATAS (
      VALUES ( SelectorY[Selection] ),
      'Calculation Group'[Name]
   )
)

It does not work, mainly because: what measure should I put instead of ?????

I thought it could be MAX('Measure X-axis'[MeasureName]) but that does not work either: no data are shown in the visual.

What am I missing? Or am I overcomplicating things?