if any query happened with ->related(array('standards','products')) then i want to filter the response with some condition, i think possible at after_load observer//
But how i check that the model include these relation joined.
If it is not, all you can do is dynamically add where clauses to the query.
Using an observer doesn't really work, since the data will already have been loaded. If you then start changing the data, the ORM will see that as a change, and might delete objects in the database if you are not careful.