The temporary folder/files (/log, /tmp, /work) could be at a different location (for eg- /home/TempJBoss/TempLogs). But, defining a custom location for the /data directory, outside of the JBoss server dir is not possible.
Even if using the system property I define -Djboss.server.data.dir=/home/TempJBoss/TempData , there will always be a /data/xmbean-attrs/ directory which gets created in /jboss-as/server/<server_name>/

Looking at the XMBean Persistence in file "jboss-service.xml" shows :

....
<attribute name="AttributePersistenceManagerConfig">

<data-directory>data/xmbean-attrs</data-directory>

</attribute>
....

The <data-directory> location can be changed but it is always relative to server home dir.
....
<attribute name="AttributePersistenceManagerConfig">

<data-directory>../data/xmbean-attrs</data-directory>

</attribute>
....

However defining an external location (/home/TempJBoss/TempLogs/data/xmbean-attrs) or ${jboss.server.data.dir}/xmbean-attrs does not works.