Yes, this is possible. First export the graph line of the first Multiband test by following this guide: viewtopic.php?f=12&t=145&start=0
Then add this reference line as a new limit line to your second Multiband test and ensure that this Limit Line is shown/enabled in your graph.
Unfortunatly i have to login as Administrator to save as limit line, an dont forget to cleanup later I got an other 15 limit lines today, but yes I like it!