I assume you mean the commented out test? It looks like it is working as it is supposed to out-of-the-box.

The purpose of Hierarchical domains is to reproduce what was done in JBoss4.x with the Hierarchical loader repositories.

So by default they work the same way.

The jboss-classloading.xml only lets you specify parent-first=true/false,

i.e. ParentPolicy.BEFORE or ParentPolicy.AFTER_BUT_JAVA_BEFORE

If you want more control on what is visible in the parent,

then you need to create the domain manually to specify your filter.

e.g. Your test works if I change it as follows:

[ejort@warjort jboss-cl]$ svn diff classloading/src/test/java/org/jboss/test/classloading/dependency/test/HierarchicalDomainUnitTestCase.java 
Index: classloading/src/test/java/org/jboss/test/classloading/dependency/test/HierarchicalDomainUnitTestCase.java
===================================================================
--- classloading/src/test/java/org/jboss/test/classloading/dependency/test/HierarchicalDomainUnitTestCase.java     (revision 101491)
+++ classloading/src/test/java/org/jboss/test/classloading/dependency/test/HierarchicalDomainUnitTestCase.java     (working copy)
@@ -23,6 +23,7 @@
 
 import junit.framework.Test;
 import org.jboss.classloader.spi.ClassLoaderSystem;
+import org.jboss.classloader.spi.ParentPolicy;
 import org.jboss.classloading.spi.dependency.policy.mock.MockClassLoadingMetaData;
 import org.jboss.classloading.spi.metadata.ClassLoadingMetaDataFactory;
 import org.jboss.classloading.spi.metadata.ExportAll;
@@ -478,7 +479,8 @@
 
    public void testExplicitRequirementsInNewDomain() throws Exception
    {
-      // FIXME - testExplicitRequirementsInDomain("SomeNewDomain");
+      system.createAndRegisterDomain("SomeNewDomain", ParentPolicy.BEFORE_BUT_JAVA_ONLY, system.getDefaultDomain());
+      testExplicitRequirementsInDomain("SomeNewDomain");
    }
 
    protected void testExplicitRequirementsInDomain(String domain) throws Exception

But in that case, there is little point in the hierarchical domain. ;-)    

system.createAndRegisterDomain("SomeNewDomain", ParentPolicy.BEFORE_BUT_JAVA_ONLY);

would give you a new top-level domain and also make your test work.

NOTE: In real life, you would use ParentPolicy.BEFORE in the last example,

but if you used that in this test, it would load the support classes from the classpath

rather than the Mock classloader. :-)