Oracle 11g hierarchical queries with limit, offset and order by to achieve pagination on the root level
With the help of Philᵀᴹ's and Joe Obbish's comments I was able to create a query based on recursive CTEs (Common Table Expressions) that allows pagination on the top level of a hierarchical table.

The SQL statement looks like this:

WITH my_hierarchy (&lt;column1&gt;, &lt;column2&gt;, ...) AS (
  SELECT &lt;column1&gt;, &lt;column2&gt;, ... 
  FROM (
    SELECT &lt;column1&gt;, &lt;column2&gt;, ... , row_number() OVER (ORDER BY &lt;order_column&gt; ASC) row_num
    FROM my_table mt
    WHERE mt.&lt;column1&gt; = 'some value'
      AND mt.&lt;column2&gt; = 'other value'
  )
  WHERE row_num between &lt;offset&gt; and &lt;offset+limit&gt; -- pagination on top level
  UNION ALL
  SELECT mt.&lt;column1&gt;, mt.&lt;column2&gt;, ...
    FROM my_table mt
    INNER JOIN my_hierarchy mh   -- recursive self join
        ON mt.parentId = mh.id
)
SELECT *
FROM my_hierarchy