Assignment method directly in the form

I would like to know if it is possible to let the user of a form choose the next one (for exemple for an approval). In my WorkFlow I used the assignment method : Manually by the person who handled.

So now when the form is completed and the user click on the “Send” button they have to choose the next user in an other page through this :

I would like to have this user interface directly at the end of the form and not in an other page. Does someone know if it is possible ?

Thank you very much.