As my understand, you want to show calculation of value for same period of Open date and Resolve date. I think you should refer topic side by side role-playing in power bi
The idea is having same date table for display but calculation will be computed by specific relationship of kind of date (open/resolve)
If it's not what you are expecting, please share me sample data and your expectation as picture. So I could quickly figure out solution.
i would consult the article posted by tringuyenminh92 - what you want is to do calculations on your dates to provide the side by side analysis of the dates. This will probably mean you need to acquire a slighly more complex understanding of how dax works.