Questions regarding first/new customer

Hey,

I guess this DAX statement used with a calculated column creates what you are looking for:

 

result = 
var currentCustomer = 'Table1'[Customer]
var currentItem = 'Table1'[Item]
var minDate = 
    CALCULATE(
        MIN('Table1'[Purchase Date])
        ,ALL(Table1)
        ,'Table1'[Customer] = currentCustomer
        ,'Table1'[Item] = currentItem
    )
    return
    IF(
        AND(
            AND('Table1'[Customer] = currentCustomer, 'Table1'[Item] = currentItem)
            ,'Table1'[Purchase Date] = minDate
        )
        ,"First Purchase"
        ,"Re Purchase"
    )

At least the new column "result" contains the same values of the column COLUMN from the sample data you provided, please note that I renamed the column from the test data to "TestResult"

 

Hopefully this is what you are looking for.

 

Regards,

Tom