Highlighting Fields - formula

Hi Alta88 

You can use "Related" in a variable before those IF conditions. 

Highlighting Flag =
VAR vAppointmentType =
    RELATED ( 'Scheduled Appointments'[AppointmentType] )
RETURN
    IF (
        ISBLANK ( 'Customer Data'[AccountNumber] ) = TRUE,
        "#F7DC6F",
        IF (
            LEFT ( 'Customer Data'[AccountNumber], 1 ) IN { "U", "E" },
            "#F7DC6F",
            IF (
                vAppointmentType
                    IN {
                        "Install - Builder - Sold Homes - LVL 1",
                        "Install - Builder - Sold Homes - LVL 2"
                    }
                        && LEFT ( 'Customer Data'[Accountnumber], 1 ) = "1",
                "#F7DC6F",
                IF (
                    vAppointmentType
                        IN { "Service - Builder - Builder Awareness" }
                            && LEFT ( 'Customer Data'[AccountNumber], 1 ) = "5",
                    "#F7DC6F"
                )
            )
        )
    )

When referencing a column, it is recommended to have its table name before the column name to indicate which table it is from. 

Best Regards,
Community Support Team _ Jing
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