Matrix column based on other matrix columns

hello markmsc 

please check if this accomodate your need.

create a couple measures for apple, pear, elm, oak, and birch.

Apple =
SUMX(
    FILTER(
        'Table',
        'Table'[Fruit]="Apple"
    ),
    'Table'[Num1]
)

Pear =
SUMX(
    FILTER(
        'Table',
        'Table'[Fruit]="Pear"
    ),
    'Table'[Num1]
)

Elm =
var _Elm = 
SUMX(
    FILTER(
        'Table',
        'Table'[Tree]="Elm"
    ),
    'Table'[Num2]
)
Return
DIVIDE(
    _Elm,
    [Apple]+[Pear]
)

Oak =
var _Oak = 
SUMX(
    FILTER(
        'Table',
        'Table'[Tree]="Oak"
    ),
    'Table'[Num2]
)
var _Melon = 
SUMX(
    FILTER(
        'Table',
        'Table'[Fruit]="Melon"
    ),
    'Table'[Num1]
)
Return
DIVIDE(
    _Oak,
    _Melon
)

Birch =
var _Birch = 
SUMX(
    FILTER(
        'Table',
        'Table'[Tree]="Birch"
    ),
    'Table'[Num2]
)
Return
DIVIDE(
    _Birch,
    [Apple]+[Pear]
)

Hi,

Please check the below picture and the attached pbix file.

I tried to implement calculation group.

Another variant
1) I created the DimFruitTree table in Power Query
3) you need to sort the FruitTree column by Index

2) The relationship is like this

markmsc 

For Fruit columns (Apple/Pear/Melon):

Fruit Measure = SUM(Data[Num1])

For Tree columns (Elm/Oak/Birch):

Tree Measure =
VAR AppleSum = CALCULATE([Fruit Measure], 'Data'[Fruit] = "Apple")
VAR PearSum = CALCULATE([Fruit Measure], 'Data'[Fruit] = "Pear")
VAR MelonSum = CALCULATE([Fruit Measure], 'Data'[Fruit] = "Melon")
RETURN
SWITCH(
SELECTEDVALUE('Data'[Tree]),
"Elm", DIVIDE(SUM(Data[Num2]), AppleSum + PearSum),
"Oak", DIVIDE(SUM(Data[Num2]), MelonSum),
"Birch", DIVIDE(SUM(Data[Num2]), AppleSum + PearSum)
)

Use these measures in your matrix with City as rows, and Fruit/Tree as columns.