Data forecast

Hi, Cocrodile 

You can try the following methods.

Measure = 
Var _AB=SUM('Table'[A])-SUM('Table'[B])
Var V2=CALCULATE(SUM('Table'[C]),FILTER(ALL('Table'),[Key]=14))
Var V3=IF(SELECTEDVALUE('Table'[C])=BLANK()&&V2<>BLANK(),V2+_AB,SUM('Table'[C]))
Var V4=IF(SUM('Table'[Key])=15,V3)
Var V5=IF(SELECTEDVALUE('Table'[C])=BLANK(),V4,SUM('Table'[C]))
return
V5

Is this the result you expect? A formula to calculate V5.

Best Regards,

Community Support Team _Charlotte

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