Is there a way to access the individual items, or format the output?
Yes, you can substitute individual field group fields using the formatting explained format.
FIELD_NAME__INDEX__FIELD_NAME
The first field name is the name of your field group field. For example lets call it cb_fieldgroup. Next the index is the row in the field group field you want to access. The index always begins with 0. Finally the last field name is the name of the field in the field group field of the specified row that you want to substitute in. For example lets call this cb_text. This gives you the below.
cb_fieldgroup__0__cb_text
Used as a raw substitution you'd have the below.
[cb_fieldgroup__0__cb_text]
This should function anywhere substitutions are supported.