Hi @sandeepstw , thanks for your reply.
I couldn't make it work with the select+join, maybe because I have complex columns (e.g., multiple choice person) and it needs some nested for each loops.
However, I could make it work with a simple Create CSV table following the Get Items, with custom columns option and this formula where I need to extract a value from each multiple choice column:
xpath(xml(json(concat('{"root":{"choices":',item()?['MultipleChoiceColumn'],'}}'))),'/root/choices/Value/text()')
xpath(xml(json(concat('{"root":{"choices":',item()?['MultipleChoicePersonColumn'],'}}'))),'/root/choices/Email/text()')
Thank you.