This must be possible.
If your form has a subform named EmployeeInfo which repeats upto thrice.
Your form's XML data will have three Tags named EmployeeInfo (in case your schema has the same tag name).
Within workbench (in your process) you can loop through based on the number of sub-form instances present inthe form.
XPATH to find the number of instances: count(/process_data/your_xml_variable/root_tag/EmployeeInfo)
Hope that helps.