Get an Latest date Records

Hi,

I tried to create a sample pbix file like below, and please check the below picture and the attached pbix file.

I used INDEX dax function in the measures.

INDEX function (DAX) - DAX | Microsoft Learn

Num expected result: = 
VAR _t =
    CALCULATETABLE (
        SUMMARIZE ( 'fact', 'calendar'[Date] ),
        REMOVEFILTERS ( 'calendar'[Date] )
    )
VAR _latestdate =
    INDEX ( 1, _t, ORDERBY ( 'calendar'[Date], DESC ) )
RETURN
    IF (
        HASONEVALUE ( state[state] ),
        CALCULATE (
            SUM ( 'fact'[num] ),
            KEEPFILTERS ( 'calendar'[Date] = _latestdate )
        )
    )

Diff expected result: = 
VAR _t =
    CALCULATETABLE (
        SUMMARIZE ( 'fact', 'calendar'[Date] ),
        REMOVEFILTERS ( 'calendar'[Date] )
    )
VAR _latestdate =
    INDEX ( 1, _t, ORDERBY ( 'calendar'[Date], DESC ) )
RETURN
    IF (
        HASONEVALUE ( state[state] ),
        CALCULATE (
            SUM ( 'fact'[diff] ),
            KEEPFILTERS ( 'calendar'[Date] = _latestdate )
        )
    )