You can use the Form Hierarchy control to launch child forms from a parent form.
Winshuttle Composer; WInshuttle Workflow.
Please find the attached parent and child solutions that will illustrate how to use Form Hierarchy.
Things to note when using this feature:
1. The button to launch a child form will appear only after the parent form has been saved and routed and will appear in the task right after the start node
2. When using in conjunction with the Form Data Exchange element, you will use this format for the fields to be copied, not the Xpath.