create clone able field.

I want to create clone able field in my new module. when a user will click on “Moment toevoegen”

then a clone of “Datum”, “Onderwerp” and “Afgesproken” field should create under the existing fields. please guide me how i can do this. please see the attachment.

Clone able field

Needs customization to get such a solution. You will need a relationship and not the normal field to store multiple fields (Datum/Onderwerp/Afgesproken)