{[
  {"departmentId": 0,
   "departmentName": "Отдел 1",
        "children": [
          {"departmentId": 1,
           "departmentName": "Отдел 1.1",
           "children": [
               {
                 "departmentId": 2,
                 "departmentName": "Отдел 1.1.1",
                 "children": [
                     {
                       "departmentId": 5,
                       "departmentName": "Отдел 1.1.1.1",
                       "children": "null"
                     }
                   ]
               }
             ]
          }],
          {"departmentId": 3,
           "departmentName": "Отдел 2",
           "children":[
             {"departmentId": 4,
              "departmentName": "Отдел 2.1",
              "children": "null"
             }
          ]
         }
  }
]}

WITH recursive parents AS (

  SELECT
    id, name, parent_id
  FROM departments
  WHERE
    id = '798c66092ef24ec488ef308291947913'

  UNION ALL

  SELECT
    dep.id, dep.name, dep.parent_id
  FROM departments dep
  JOIN parents ON parents.parent_id = dep.id
)

SELECT
  *
FROM parents
WHERE id != '798c66092ef24ec488ef308291947913'
--order by id;