datediff between two separate columns and two diffrent record

Hi sapirmarko ,

I suggest you to create a measure by below code.

Diff =
VAR _ADDRANK =
    ADDCOLUMNS (
        'Table',
        "Rank",
            RANKX (
                FILTER (
                    'Table',
                    'Table'[whs_id] = EARLIER ( [whs_id] )
                        && 'Table'[outlet_id] = EARLIER ( [outlet_id] )
                ),
                'Table'[order_ceated_date],
                ,
                DESC,
                DENSE
            )
    )
VAR _ADDDIFF =
    SUMMARIZE (
        _ADDRANK,
        [whs_id],
        [outlet_id],
        "Diff",
            VAR _CURRENT =
                MAXX (
                    FILTER (
                        _ADDRANK,
                        [whs_id] = EARLIER ( [whs_id] )
                            && [outlet_id] = EARLIER ( [outlet_id] )
                            && [Rank] = 1
                    ),
                    [order_ceated_date]
                )
            VAR _PREVIOUS =
                MAXX (
                    FILTER (
                        _ADDRANK,
                        [whs_id] = EARLIER ( [whs_id] )
                            && [outlet_id] = EARLIER ( [outlet_id] )
                            && [Rank] = 2
                    ),
                    [paid_date]
                )
            RETURN
                DATEDIFF ( _PREVIOUS, _CURRENT, DAY )
    )
RETURN
    SUMX ( _ADDDIFF, [Diff] )

My Sample:

Result is as below.

Best Regards,
Rico Zhou

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