Need help for improving my dax

here's a "simplified"  version of your measure.

Bonus Campus = 
VAR NewstdPD = SUM ( 'Campus'[# of New Student PD] )
VAR TargetNewStdPD = SUM ( 'Campus'[# of New Enrol PD Target] )
VAR pct_stdvstarget = DIVIDE ( NewstdPD, TargetNewStdPD )
VAR new_std_pd_reopen_pct = SELECTEDVALUE ( 'Campus'[% New Std PD And Re Open vs Target] )
VAR new_std_pd_new_enrol_pct = SELECTEDVALUE ( 'Campus'[% New Student PD vs New Enrol PD Target] )
VAR CampusCode = SELECTEDVALUE ( Campus[Campus Code] )
VAR CurrentGroup = SELECTEDVALUE ( Bonus[Group] )
VAR K = SELECTEDVALUE ( 'Bonus'[Date] )
VAR datekey = CALCULATE ( MIN ( 'Date'[Date Key] ), 'Date'[Date Key] = VALUE ( K ) )
VAR BonusLevel =
    SWITCH (TRUE (),
        new_std_pd_reopen_pct >= 1.1, 3,
        new_std_pd_reopen_pct >= 1.0, 2,
        new_std_pd_reopen_pct >= 0.9, 1
    )
VAR Bonus_campus = 
    LOOKUPVALUE (
        'Bonus'[Bonus ],
        'Bonus'[Campus], CampusCode,
        'Bonus'[Level ], BonusLevel,
        'Bonus'[Group], CurrentGroup
    )
RETURN
    SWITCH (TRUE (),
    new_std_pd_new_enrol_pct < 0.7, BLANK(),
    new_std_pd_new_enrol_pct >= 0.8, Bonus_campus,
    BonusLevel = 3 && CurrentGroup in { 1,2 }, MAX ( 0, Bonus_campus - 6000000 ),
    BonusLevel = 3 && CurrentGroup = 3, MAX ( 0, Bonus_campus - 4000000 ),
    BonusLevel = 3 && CurrentGroup in { 4,5,6 }, MAX ( 0, Bonus_campus - 3000000 ),
    BonusLevel = 3 && CurrentGroup = 7, MAX ( 0, Bonus_campus - 1000000 ),
    BonusLevel = 1 && not CurrentGroup in { 6,7 }, 0,
    CurrentGroup in { 6,7 } ,MAX ( 0, Bonus_campus - 500000 ),
    MAX ( 0, Bonus_campus - 2000000 )
    )

 I think your LOOKUPVALUE can be replaced with a CALCULATE  but I don't fully understand the logic behind your data.