I have encountered an error that in filter-def definition in condition attribute is not possible to use SQL function trim with expression.
For example this definition: <filter-def name="concatInTrim" condition="TRIM(CONCAT(TITLE,TITLE)) IS NOT NULL" /> causes this error:

------------------------------------------------------------------------------- Test set: org.hibernate.test.function.trim.FunctionTrimTest
------------------------------------------------------------------------------- Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.698 sec <<< FAILURE!
testBasicUsage(org.hibernate.test.function.trim.FunctionTrimTest) Time elapsed: 0.659 sec <<< ERROR!
org.hibernate.HibernateException: Unexpected number of trim function operands : 5
at org.hibernate.sql.Template$TrimOperands.<init>(Template.java:582)
at org.hibernate.sql.Template$TrimOperands.<init>(Template.java:561)
at org.hibernate.sql.Template.renderWhereStringTemplate(Template.java:248)
at org.hibernate.util.FilterHelper.<init>(FilterHelper.java:63)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:737)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:133)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:84)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:284)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1842)
at org.hibernate.test.function.trim.FunctionTrimTest.setUp(FunctionTrimTest.java:24)
at junit.framework.TestCase.runBare(TestCase.java:132)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:59)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:115)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:102)
at org.apache.maven.surefire.Surefire.run(Surefire.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:350)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)

I think, that this problem is caused by function org.hibernate.sql.Template.renderWhereStringTemplate(), that doesn't take into account possibility of expression in trim function argument.
I think that this problem is related to http://opensource.atlassian.com/projects/hibernate/browse/HHH-5676?page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#issue-tabs.
In attachment is test case based on Hibernate tutorial (hbm.xml Tutorial).