To be completely honest, I’m not sure about the answers to your questions. There are several function in ACF that are used internally and not documented on this site. acf_get_field() is one of those. These functions can take arguments.
acf_get_field_group() is another of these functions.
and another is acf_get_fields($group_key), which will return an array of all of the fields in a groups, including sub fields, and I’m assuming this would include clone fields.
Like I said in my original answer, I don’t know exactly how to do what you want to do, but somehow ACF must know do something to tell it how the clone field is related to the parent group.
