Dashboard Designer/Office 365

Is there a way to connect to multiple data sources (lists) and display in a single chart?

I have six sub-sites and need to pull pieces of data from each list into a single roll-up/dashboard page that is only viewed by the Administrator.

Sub 1 - List
Sub 2 - List
Sub 3 - List
Sub 4 - List
Sub 5 - List
Sub 6 - List

Dashboard: Display single chart with data from each of the sub-sites

Thank you for the question.
Sure, you can either retrieve data from multiple sites via REST or CSOM api via JavaScript in init handler or you can gather it through PowerShell and publish as a single file to the target site as we did for a public site and use it as a data source for the chart. Our support team will be glad help you with this task. Just drop the detailed requirement to support@spchart.com and we will estimate them.