Date differences between dates with different status

Hi,

Please check the below picture and the attached pbix file.

Expected result: =
VAR firstrequesteddate =
    MINX (
        FILTER (
            Data,
            Data[UID] = MAX ( Data[UID] )
                && Data[ACTIVITY_TYPE] = "REQUESTED"
        ),
        Data[ACTIVITY_DATE]
    )
VAR firstrespondeddate =
    MINX (
        FILTER (
            Data,
            Data[UID] = MAX ( Data[UID] )
                && Data[ACTIVITY_TYPE] = "RESPONDED"
        ),
        Data[ACTIVITY_DATE]
    )
RETURN
    VALUE ( firstrespondeddate - firstrequesteddate )

If you mean to create a calculated column, here is a similar apporach:

DaysToFirstResponse = 
VAR FirstRequestDate = 
    CALCULATE (
        MIN ( 'Table'[ACTIVITY_DATE] ),
        ALLEXCEPT ( 'Table', 'Table'[UID] ),
        'Table'[ACTIVITY_TYPE] = "REQUESTED"
    )
VAR FirstResponseDate = 
    CALCULATE (
        MIN ( 'Table'[ACTIVITY_DATE] ),
        ALLEXCEPT ( 'Table', 'Table'[UID] ),
        'Table'[ACTIVITY_TYPE] = "RESPONDED"
    )
RETURN
    DATEDIFF ( FirstRequestDate, FirstResponseDate, DAY )

 
Sample file available here.
Please mark this as a solution if it resolved your issue.

Regards