With the information you have, I would just check YES and enter the full name with place and date of filing. If you don’t know the date for sure, at least try to put month/year. Even just the year should be O.K.
Example:
First/middle/last name, spouse I-130, CSC 07/02, Approved (A# Unknown)
The enclosed copy of your divorce decree will provide more information to support this entry.
Ray