repeating section is pure NINTEX forms structure, sharepoint doesn't recognize it OOTB.
usually repeating section from form is stored/connected to 'Multiple lines of text' sharepoint field (foramtted as plaintext). it saves as XML structure.
if you really want repeating section is recognized as field type you need to install some 3rd party plugin. have a look on this thread for a possible solution.
Thanks Marian, I would like to show the the items at the repeating section in my view list but then we have to install 3rd party.
Are there any other solutions to view items in the repeating sections without 3rd party?
yes they are, but they needs custom scripting.
one approach might be that you customize your page with list view web part and add script editor web part. within script web part you can write a script that will convert repeater XML into a HTML table.
you can find example of this eg here Show Repeating Section as table in List View
the other approach (recommended from (I guess) SP2013) is to use CSR/JSL links.
examples you can find eg here