How can I create a multi-module Maven project with modules based on existing sources via the IntelliJ GUI?

I would like to create a multi-module maven project where each module is based on existing sources.

I have created the project via "New -> Project -> Maven" and named it "ABC". When I right-click the "ABC" module in the project view and click "New -> Module", I am able to create new modules and I am able to choose "ABC" as their parent. Maven-wise, this works as expected, which means that the POM of "ABC" is created as Aggregate POM which contains all the sub-modules.
But I do not want to create completely new sub-modules, I want them to be based on existing sources. I found no way to add new sub-modules based on existing sources via the GUI. 

Is there even a way to do this via the GUI? (I know that it is still possible to do this by manually editing the aggregate POM of "ABC", but I would also like to be able to describe a way via the GUI for my colleagues.)