DAX Variable Scope - Cannot create variables within the correct row context

^{Hi BryonScruggs ,}

^{Please follow these steps:}

^{(1) Create a new Table}

Employment Cases = 
VAR PeriodStart =
    DATE ( 2022, 01, 01 )
VAR PeriodEnd =
    DATE ( 2022, 03, 31 )

RETURN
    ADDCOLUMNS (
        SELECTCOLUMNS (
            attr_Tkpr_vw,
            "EmpID", attr_Tkpr_vw[TkprNumber],
            "Hire", attr_Tkpr_vw[TkprDateHire],
            "Term", attr_Tkpr_vw[TkprDateTerm],
            "Hire Test",
                CALCULATE (
                    MIN ( attr_Tkpr_vw[TkprDateHire] ),
                    ALLEXCEPT ( attr_Tkpr_vw, 'attr_Tkpr_vw'[TkprNumber] )
                ),
            "Term Test",
                CALCULATE (
                    MIN ( attr_Tkpr_vw[TkprDateTerm] ),
                    ALLEXCEPT ( attr_Tkpr_vw, 'attr_Tkpr_vw'[TkprNumber] )
                )
        ),
        "Employment Period",
            SWITCH (
                TRUE (),
                AND ( AND ( [Hire] >= PeriodStart, [Hire] <= PeriodEnd ), [Term] >= PeriodEnd ), DATEDIFF ( [Hire Test], PeriodEnd, MONTH ),
                AND (
                    AND ( [Hire] >= PeriodStart, [Hire] <= PeriodEnd ),
                    AND ( [Term] >= PeriodStart, [Term] <= PeriodEnd )
                ), DATEDIFF ( [Hire Test], [Term Test], MONTH )
            )
    )

^{(2)Final output}

^{If that's not what you need, please share the sample file}

^{Best Regards,}

^{Gallen Luo}

^{If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.}