Auto populate Repeating Section based on the Single line text input

This can be done with JavaScipt which is possible in the product but not supported. Meaning you're on your own, but hey thats why you're in the community :-)

I see you decided for responsive design...

if you'd like to show dynamic number of rows for a given client code you can forget to achieve anything like that in responsive forms.

if number of rows is constant, you'd need to add to the design as many controls as number of rows and columns you'd like to show.

with classic design, you could write a javascript that queries the other list and populates the repeating section.

if you're not stick to a repeating section, resp. you just want to show but not edit clients data you could use list view control - which would be much easier and straight forward solution.

but neither of those are available in responsive forms.

@emha  both of those and the original post is referencing classic forms designer because javascript isn't supported in responsive forms. 

I appreciate your responding and offering advice, but not quite sure why the negative tone regarding responsive forms. It doesn't even merit this use case and Nintex provides options for different use cases as needed. 

@eharris04, 

both of those and the original post is referencing classic forms designer because javascript isn't supported in responsive foms. 

have a closer look at pictures attached to the question....

there are handles around the controls that are only present in responsive designer

I appreciate your responding and offering advice, but not quite sure why the negative tone regarding responsive forms.

that's not negative tone, that's simply fact.

my personal rough estimation would be it miss half the functionality of classic forms.

and do not allow javascript so that one could work around it.

of course, there are as well advantages of responsive design, but IMHO limitiations outweight positives (so far)

sure, everybody can decide which of the two is more suitable for a specific use case. if one decides for or is obliged to use responsive forms s/he has to aware of limitations as well.

and so I provided hints for both possible designs