Currently a bundle entry e.g. looks like 


    <bundle-target>
       <destination-base-dir name="Deploy Directory">
          <value-context>pluginConfiguration</value-context>
          <value-name>homeDir</value-name>
       </destination-base-dir>
  </bundle-target>

Now to say " I want x " below the home directory I have to create a new plugin config property 'foo' , 
set it to $homeDir/x and use foo. Same for drift.

It should be possible to say 

   <bundle-target>
       <destination-base-dir name="Deploy Directory">
          <value-context>pluginConfiguration</value-context>
          <value-name>${homeDir}/${config}/deployment</value-name>
       </destination-base-dir>
  </bundle-target>

and have the ${} expressions replaced accordingly