Dynamic Product Name Combinations and Display for Each Customer Using DAX in Power BI

Hi, Lopez0090 

You can try the following methods.
Column:

Item Column = CONCATENATEX (
    CALCULATETABLE ( VALUES ( 'Table'[Items] ),
        FILTER ( ALL ( 'Table' ),
            [CustomerID] = EARLIER ( 'Table'[CustomerID] ) ) ),
    [Items],
    "/"
)

Measure:

CustomerID_Count = CALCULATE(COUNT('Table'[Item Column]),ALLEXCEPT('Table','Table'[CustomerID],'Table'[Item Column],'Table'[Year]))

Your original Measure needs no change.

Please see the attached.

Best Regards,

Community Support Team _Charlotte

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