
The above is the expected matrix in Power BI. I have to get the additional heading "MED" and "RX" for the columns "Paid" and "Unpaid" as shown in the matrix.

The above is the actual table schema, which is connected to get the data into the matrix.
How to get the column heading "MED" and "RX" in Matrix?
You should put MED/RX and Paid/Unpaid attributes in separate columns, so make sure the data is transformed to look like this:
Then put
Insuranceto the rows of the matrix,TypeandPaidas columns andValuesas values, and enable the drill mode: