Scroll bar data on two separate charts

Hi I need some help. I've Andy Pope's 'scroller' to create a chart which works very well for me. The only thing is, I don't understand how it works. I'm now trying to create a copy of the chart which is related to different data, but I don't know how to change the data reference because it's a SERIES, and I can't figure out how it works. I've attached the file - please see yellow highlighted area (it doesn't look pretty at the moment as I'm in the middle of playing around with it).

If someone could point me in the right direction it would be much appreciated. My next goal is to create about ten charts on the same sheet all referring to their own set of data, but controlled by the same scrollbar.

OK I'm confused though because when I look at the data source for the chart there is only one name, 'LEVEL'. I was expecting two, 'LEVEL' and 'EASTINGS'.