DAX formula to return main category of a line

[AxelKAp]

Hi everyone, 

Context: I have a table with Purchase Order Number, the Category (Electricity, Transport, ..., the Amount). One Purchase Order can have one or many Category. I would like to return the main category of a Purchaser Order Number, that is to say the category with the most spend. See below a sample with what I would like to have.

Do you have any idea to help ? Thanks in advance for your support !

[tamerj1 · Accepted solution]

Hi @AxelKAp 

Please try the following calculated column 

Main Category =
MAXX (
TOPN (
1,
CALCULATETABLE ( 'Table', ALLEXCEPT ( 'Table', 'Table'[PO Number] ) ),
'Table'[Spend]
),
'Table'[Category]
)