My idea here is that you need to break out the MetricWeek1 and 2 columns but also have them be aware of Metric field. You may be able to also do this with a sumOver function.
Thanks for the input! I tried this and i think it might work. Only issue I am facing is the value after division is not correct. for eg, 473/440154 = 0.001074 but the calculated field is giving rounded value 0.001000.