I tried but did not get the query (dynamic broker query) by writing debug/logs in eventviewer from the application dll or from the broker logs. The query interacts with the legacy Content Delivery APIs (e.g. Tridion.ContentDelivery.DynamicContent.Query)for the desired query and query objects are used here.
Then, using SQL profiler with minimum load on the server, I got the query as mentioned below:
use stridion_broker
go
SELECT DISTINCT ITEMS.ITEM_REFERENCE_ID, ITEMS.PUBLICATION_ID, ITEMS.ITEM_TYPE
FROM ITEMS
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN4 ON ITEMS.ITEM_REFERENCE_ID=JOIN4.ITEM_REFERENCE_ID
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN5 ON ITEMS.ITEM_REFERENCE_ID=JOIN5.ITEM_REFERENCE_ID
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN6 ON ITEMS.ITEM_REFERENCE_ID=JOIN6.ITEM_REFERENCE_ID
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN7 ON ITEMS.ITEM_REFERENCE_ID=JOIN7.ITEM_REFERENCE_ID
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN8 ON ITEMS.ITEM_REFERENCE_ID=JOIN8.ITEM_REFERENCE_ID
INNER JOIN ITEM_CATEGORIES_AND_KEYWORDS JOIN9 ON ITEMS.ITEM_REFERENCE_ID=JOIN9.ITEM_REFERENCE_ID
WHERE (ITEMS.SCHEMA_ID=(tcmid of schema)
AND ITEMS.PUBLICATION_ID=(tcmid of publication)
AND JOIN4.CATEGORY=N'Product Filters'
AND JOIN4.KEYWORD=N'20ppm Mono'
AND JOIN5.CATEGORY=N'Product Filters'
AND JOIN5.KEYWORD=N'0-10k'
AND JOIN6.CATEGORY=N'Product Filters'
AND JOIN6.KEYWORD=N'A4'
AND JOIN7.CATEGORY=N'Product Filters'
AND JOIN7.KEYWORD=N'Colour'
AND JOIN8.CATEGORY=N'Product Filters'
AND JOIN8.KEYWORD=N'20ppm Colour'
AND JOIN9.CATEGORY=N'Product Categories'
AND JOIN9.KEYWORD=N'Printers Black and White'
)
Thanks to all for helping and indicating towards the problem.