Hi @Anonymous ,
Based on your description, you can create some calculated columns as follows.
MaxDate = CALCULATE(LASTNONBLANKVALUE('Fact'[OrderDateTime],MAX('Fact'[OrderDateTime])),ALLEXCEPT('Fact','Fact'[ID]))
Islatest = IF([OrderDateTime]=[MaxDate],"Latest","Older")
Hope that's what you were looking for.
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.