Subtract 2 measures of different dimensions

[#1]

Hi,

I'm new to Qlik Sense. I'd like to subtract the values of 2 measures related  to different dimensions (that are both a calendar that goes from 1/04/17 to 30/07/2017, but they cannot be directly linked to each other in order not to generate loops in the data structure).

So If I have "5" on 5/6/17 (of calendar_1) in the first table and "7" on 5/6/17 (of calendar_ 2) in the second table, I want a graph showing "-2" in correspondence with 5/6/17. How can I do?

Waiting for suggestions and help

Thanks,

Carla