Interactive charting

Hi,
I'm developing an interactive scatter plot. I'd like the user to be able to select individual points to plot, but also select groups to plot.

For example (from attachment:
Level 1 contains Alliant
Level 2 contains Adcom, NetComp, Network Services, Network Solutions Provider

Right now, I have it where users can select individual points (Alliant, Adcom, NetComp, etc.), but I also want to add the capability for users to select Level 1, 2, 3, or 4 and their corresponding points would automatically populate, or whatever group they choose.

Thanks for your help!

Sample1.xlsm