Here is an example of a search argument that finds text documents where search term IBM occurs in the subsection H2 of structured documents.
SELECT CATEGORY, DATE
FROM DB2EXT.HTMLTAB
WHERE CONTAINS(HTMLFILE,
'SECTIONS ("H2") "IBM"') = 1
Note that section names are case-sensitive. Ensure that the section name in the model file and in the query are identical. See Working with structured documents for more information.