How to implement three level mapping?
Your question seems like a variation of this Master Summary with drill down: change "Schools" by "States" and "Domains" by "Cities" to understand what I mean.

To illustrate the "drilldown" feature of it, just click, for any of the states included, on either the corresponding column (in the chart) or link (the Total in the tabular report below the chart). If you do so (e.g. for state "IL"), you'll get the details (another tabular report) for the state you selected. If on the last tabular report you want to switch to the details for another state (e.g. for state "Florida"), use the pull-down selection list within "Parameters" (near the top of the report), and change the selected value to "Florida".

Even though the sample here doesn't allow you to do so, it would be straight forward to replace the "number of users" for each of these cities to yet another hyperlink to another report (eg to provide the details of each of the users).

To further enhance the user experience, you can optionally combine this with the (amazing) dataTables jQuery plugin. A working sample of it (that you can use to experiment with it) is shown in the Customized Simple Table of States.

The magic behind this kind of drill down reports is NOT Views, but instead it is the Forena Reports module. One way of using it, is as a  Views display format.

For more details about this module, refer to its Community Documentation. Or have a look at the module's documentation that comes with it, as in this demo site also.

Disclosure: I'm a co-maintainer of this module.