Indexing Not working Properly - Dax Measure

Try this...

Previous Mileage = 
VAR __currentTECO = SELECTEDVALUE('Vehicle Mileage'[Mileage at TECO])
VAR __currentEquipment = SELECTEDVALUE('Vehicle Mileage'[Equipment])
VAR __currentMntPlan = SELECTEDVALUE('Vehicle Mileage'[MntPlan])
VAR __result =
    CALCULATE(
        MAX('Vehicle Mileage'[Mileage at TECO])
        ,FILTER(
            ALL('Vehicle Mileage')
            ,'Vehicle Mileage'[Equipment] = __currentEquipment
                && 'Vehicle Mileage'[MntPlan] = __currentMntPlan
                && 'Vehicle Mileage'[Mileage at TECO] < __currentTECO
        )
    )
RETURN __result

Hi,

I tried to create a sample pbix file like below, and tried to use offset dax function in the measure.

Please check the below picture and the attached pbix file.

Prev. mileage: = 
SUMX (
    OFFSET (
        -1,
        ALL (
            vehicle[equipment],
            vehicle[mintplan],
            vehicle[uniqueID],
            vehicle[mileage]
        ),
        ORDERBY ( vehicle[mintplan], ASC ),
        ,
        PARTITIONBY ( vehicle[mintplan], vehicle[equipment] )
    ),
    vehicle[mileage]
)

Hi Jihwan,

This worked a treat. Many thanks for your help.