Custom Matrix subtotals

HI Anonymous,

You can create new table with current row category value and custom subtotal that you want to add to the matrix and use this field as matrix row to replace the raw table field.

Then you can write a measure formula to check the current row content value and use this as condition lookup and summary original table values, and return the custom expression result if current row contents equal to the new custom values.

You can also take a look at the following blog if it helps for your scenario:

Creating a “custom” or “hybrid” matrix in PowerBI  
Regards,

Xiaoxin Sheng