Thanks for raising this here in our community. Though we don't support this out-of-the-box, one way to bring this in is by adding a custom dashboard with the selected monitor group.
Here's how you do it
1. Under Home tab > Dashboards > Create a new dashboard (click on the create new link).
2. Choose Multi monitor Performance widgets widget type > Filter your monitor group > Choose monitor type as website > Select the monitors > Drag the attribute you want to visualize.
Below is a widget I created.
With this you should be able to visualize your group's websites. Does this solve your problem? Feel free to get back to us.
Product Manager, Site24x7