JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
The logic on the form by my colleague was to add the fields up to which we want to allow new fields to show (for example in his form, my colleague has added 3 times the same 3 fields).
Then he hid the other fields using the conditions: Smart Forms Using Conditional Logic
and this: Hide or Show Multiple Fields at Once
Now this is very simple to do with few fields, but if you wish to repeat multiple fields at the same time I would recommend checking out the following guides:
Doing it that way will allow you to easily create 'groups' of fields to manipulate and to also show / hide them in the same manner.
The Form Collapse tool is quite useful to have the group shown or hidden at the same time with the option of additional shown / hidden fields being shown as well without any complex conditions.
Of course, if you have any questions in regards to this, do let us know and we would be happy to answer your questions :)