Currently such visualization is not supported by the Graph item.
Please check if the new Graph interactivity feature satisfies your requirements. For instance, in the attached XML report definitions we have created a pie chart in PiePie.trdx and added drillthrough report action on its series. Thus from each pie you can navigate to other report(NextPie.trdx) displaying a subset of data.
I hope this helps.
Have you tried the new visualization options in Telerik Reporting Q2 2013? You can get them from your account.