Find operating units for a legal entity :

SELECT   organization_id operating_unit,
         name,
         business_group_id,
         SUBSTR (set_of_books_id, 1, 10),
         SUBSTR (legal_entity_id, 1, 10),
         date_from,
         date_to
  FROM   hr_operating_units
 WHERE   legal_entity_id = 204
/

To find SOBs set up in the instance :

SELECT   set_of_books_id,
         name sob_name,
         chart_of_accounts_id,
         chart_of_accounts_name,
         period_set_name calendar_period,
         accounted_period_type,
         user_period_type,
         currency_code
  FROM   gl_sets_of_books_v
 WHERE   set_of_books_id = 1
/

Find legal entities associated with a SOB

SELECT   organization_id legal_entity_id,
         business_group_id,
         name,
         date_from,
         date_to,
         set_of_books_id,
         vat_registration_number
  FROM   hr_legal_entities
 WHERE   set_of_books_id = 1
and business_group_id=202