Plot X & Y value on scatter plot based on cell value

Hi everyone,

Looking for some help on how to plot X & Y values on a scatter plot based on a cell value. I've got a lot of data for usage of a product and would like to visualise where it is being used most within specific regions of the country. I have created a dashboard which displays a regional map based on a drop down list and I now want to overlay the scatter plot onto this but only plot the X-Y value based on the value in the drop down list.....does that make sense??

I've attached a sample spreadsheet (I've not included the maps to cut down on size)

I think I essentially need a dynamic chart in which the "Chart Data Range" is formula based and references cell B1 on the Dashboard tab. This is something completely new for me so any help (in simple language please!) would be hugely appreciated.

Thanks in advance