How To Find Backhauls (Reverse Lanes) Between Two Flow Maps

Hello,

I am new to Power BI, but have been learning as fast as I can to help our Sales Org grow. I am in the logistics industry (USA trucking/transportation), and have found flow maps very useful internally, but especially customer-facing. 

So far I have figured out how to export our network data onto a flow map, as well as the customer's network/bid data onto a separate flow map, but what I am looking for is a way to find what we call "backhauls" or reverse lanes/synergies between the two networks. Another user, eswanzy , had a similar question a few years ago: https://community.powerbi.com/t5/Desktop/Calculate-number-of-reverse-lanes-in-same-table-keeping-slicers/m-p/825977

Any help or ideas are appreciated. Thank you.