Use this dialog to create configurations containing multiple run/debug configurations that you can launch at once. This is useful, for example, if you want to launch various automated tests. Each configuration will be available in a separate tab in the Run or Debug tool window.
Click to select which of the existing configurations you want to include into the Compound configuration, and fill in the following fields:
In this field, specify the name for the run/debug configuration. The name will help you identify the created configuration when you choose to edit it later, or when you invoke it, for example, from the Run popup Ctrl+Shift+Alt+R.
Share through VCS
Select this checkbox to put the run/debug configuration under version control and make it available to other team members.
The shared run/debug configurations are kept in separate xml files under .idea\runConfigurations folder, while the local run/debug configurations are kept in the .idea\workspace.xml .
Another case where the Compound run configuration could be very useful is running/debugging a front end web application and a backend REST service at the same time. With the debugger attached, this will let you set a breakpoint in any of the projects and debug the entire flow of the application: