PowerBi Slicer and Matrix Visualisation Issue

Hi Anonymous ,

Please try this:

New Table as slicer:

Subject = VALUES('Table'[Subject])

A measure:

Subject with AND-Only Condition = 
var selectedSubject=VALUES(Subject[Subject])
var countRowsFact=
COUNTROWS(
    DISTINCT(
        SELECTCOLUMNS(
            FILTER(
                'Table',
                RELATED(Subject[Subject]) in selectedSubject
                ),
                "Subject",
                RELATED(Subject[Subject])
        )
    )
)
var countRowsSubject=COUNTROWS(selectedSubject)
return
IF(countRowsFact>=countRowsSubject,countRowsFact)

https://radacad.com/slicer-with-and-condition-in-power-bi#:~:text=The%20default%20behaviour%20of%20the,%E2%80%9D%2C%20OR%20%E2%80%9CBlue%E2%80%9D.