Calculation group sorting by Group & Metric

Hi There,

I've got a very specific request for PowerBi Desktop. I have the following set of dummy data:

I am building a tracker to see week by week how sales, units, and traffic have changed. Here is report demo link:
https://drive.google.com/file/d/1K-xL6F2Km2k-ZU9XanKZ4vbTi8b6oWCS/view?usp=sharing

I've created measures for the current week, prior week, Delta change (Δ), and percentage change (Δ %) for each metric. 

The goal is to create a matrix with all the metrics with the ability to filter to a certain topic (sales, units, traffic) and with the ability to sort the table by any metric within those topics. 

Without calculation groups, in Table 1 I can create the output I'd want, with the ability to sort sales Δ. However, this doesn't solve the issue of needing to filter to just sales or see side by side sales with traffic for example. 

In Table 2 I can use calculation groups to create a similar output, with the ability to filter by a CalcGroup option (Sales, Units, Traffic) in order to hone in on that topic. I can even sort by a metric, but not by a metric via a topic. By that I mean I can sort by Δ, but I can't sort by Traffic Δ. I need a way to sort the matrix specifically by a specific metric within a specific topic. 

Images are attached to show this issue. I've read online how to sort by a calculation group, but it does include headers or multiple metrics within the group. I've used dummy data to narrow it down to 3 topics but in actuality there are about 12 total - which is why I need a way to hone them down using CalcGroups.

Below are screenshots of the TabularEditor code and the entire dashboard.