1) First set up a data source connection to the "test" source only, put data together in your worksheet.
2) Then under "Data" tab > New Data Source > add both data sources and set up a JOIN and go from there. Once you set both up, under your Data pane you should see both data sources like this, one would be an individual source (top one) and the other with '+' is the JOINed (bottom one). Hope this helps.
Thank you very much for your help.