How many calls at the same time?

Hi virus190 ,

This is caused by calculation logic. Unavoidable. ☹️ Maybe others 

In addition, I modify the expression a bit and it will be slightly better.

Column 2 =
VAR _1 = [Accepted]
VAR _2 = [Hang up]
RETURN
    IF (
        NOT (
            ISEMPTY (
                FILTER (
                    'Table',
                    'Table'[CALL ID] < EARLIER ( 'Table'[CALL ID] )
                        && _2 >= [Accepted]
                        && _1 <= [Hang up]
                )
            )
        ),
        "x"
    )

Or you can try to create a measure:

Measure =
VAR _1 =
    MAX ( [Accepted] )
VAR _2 =
    MAX ( [Hang up] )
RETURN
    IF (
        NOT (
            ISEMPTY (
                FILTER (
                    ALLSELECTED ( 'Table' ),
                    'Table'[CALL ID] < MAX ( 'Table'[CALL ID] )
                        && _2 >= [Accepted]
                        && _1 <= [Hang up]
                )
            )
        ),
        "x"
    )

Best Regards,

Icey

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