So I would advise to get your data into the "right" shape (so that Sales and Transactions are on different Columns/Fields, against a single row per Transaction)
However we can work with this, it's just more work!
So first I want to create your individual Sales and Transactions Columns;
IIF([Dmdunit] != 'Transaction Counts',[Sales],NULL)
[Transaction Counts Only]
IIF([Dmdunit] = 'Transaction Counts',[Sales],NULL)
Once we have this we can aggregate the results, and so display at whatever level you want...
SUM([Transaction Counts Only]))
hope that helps.
Thanks SImon, works perfectly! Thanks for the support!