Adding group of fields in custom module I am trying to programmatically create a content type with 2 fieldsets, where the second one have an "Add more" option to create multiple set of fields. I looked for a working example to create multiple sets of fields, save, and edit them. Unfortunately, I couldn't find any. My module is creating, editing and saving the content type without 'add more' option.

Can anybody help?
I hate to say that there is an only way that I know to have multi-value field groups in Drupal 7 is Field Collection module. It is based on Entity API. It creates a new entity of which you can add any number of fields, and attaches that to the content type or any other entity you create.