To keep the default values of the step one form after successfully submitting the step 2 form, here is an easy way. Just pass the form state values of step 1 form as query parameters to the same page on submitting step 2 form. Set the default values of step 1 form as, first check whether the form_state value is set. If yes, set the default values of step 1 form fields with the form_state values. Else check the URL query parameters, whether this variable is set. If yes, then set the default value with that value.