Two Grid meters on same Grid - Solar consumption

I have two distribution boxes tied to the same grid (let’s call them A and B). Both are measured with a Shelly Pro 3em. I cannot measure A + B with one shelly, because I don’t have access to the Grid cabinet (not sure about the correct term).

Now, if I simultaneously consume on B, and produce (solar) on A, in the energy dashboard, the production is listed as exported, and the consumption as imported. Which is technically correct, but not what I want since it’s the same grid, and I can use my own energy:

A + B both have consumption, only A has production, but this might change.

Is there a way to configure this so i can see the effective export/import?