I've been trying to import lists with entries which live in multiple entry custom fields, but couldn't work out how to import them. But I have now and thought I'd share it with you.
Cutting to the chase, use double pipes ie || between the options. So for a list that has three fields (the third being a custom field with multiple options)
name, email address, option1||option2||option3||...||option n
Hope this helps.
Thanks so much for sharing that and apologies if it was tough to track down. We explain this i the help docs here:
But perhaps we need to make that easier to find from within your account.