Purchase Order Dashboard

I'm stuck and need help to create a PO dashboard for a client. 

Here's the process.

I receive multiple PO's from the client with different PO amounts. I need a dashboard that displays the PO Qty, PO transactions and PO balance.

Here's where I'm struggling.

I have an excel spreadsheet in SP that I connect to via Power BI to track PO transactions by year and month.

I created a Matrix visual that shows the PO transactions by year/month and the subtotal but I can not figure out how to create a measure or calculation to display the original PO quantity and the PO balance.

Any suggestions?

with the below output info.

• PO Amount
• PO A