It looks like you were really close! I just changed your filters to use the desired fields instead of the parameter. I did leave them as table calculations as that is required to keep the week data from the source and get the average over multiple weeks.
The calculations looks like: LOOKUP(ATTR(Country), 0)
Also, the other table calculations need to be computed along Week.
Thanks Shawn & Joshua. Your suggestion is properly working in my report. Thanks once again.
You're welcome! Glad to help!