Overlaying scatter plots with R

Thanks to those who replied, I appreciate it. I did find a semi-workaround: I backtracked a bit and created a mega-dataframe (for the grayed out #create dataframe area--I just incorporated every single datapoint I wanted on my final graph into one huge dataframe mess), then created some mini dataframes using R within the script editor, applied some filters to these mini dataframes according to what I wanted from each, and then merged these separately filtered dataframes back into one dataframe for the final graph.

But if anyone at Microsoft is listening, it would have been much simpler to allow for more than one dataframe from the start.  I'm still not able to get exactly what I want.