Hi @kenw232 ,
I just came across your question and hopefully I am able to help here.
I don’t believe you can query these actual values directly (but I could be wrong). My first thought here would be to actually get this data directly by calling on the Shopify API. You could either setup an Order Created webhook and sum the values (merging the data by email) or poll orders (REST or GraphQL).
The other option if you want to stick only to Klaviyo would be to poll the Events API using the Metric ID (The actual metrics can be found here in the Klaviyo account - for Shopify you would use the Placed Order one):
https://www.klaviyo.com/metric/METRICID/placed-order
You’d still need to SUM them together here though.
One other thing you could consider here (I haven’t used this yet) is using the Query Metric Aggregates API - although I believe this has a 1 year maximum date range. More info on that here.
Hope this helps!
Thanks
David