Use Jmeter’s base directory

You can access these variables using Beanshell as follows:

1. JMeter’s base dir

   import org.apache.jmeter.services.FileServer;
   
   String baseDir = FileServer.getFileServer().getBaseDir();
   vars.put("baseDir", baseDir);
   

2. JMeter’s script location (GUI mode)

   import org.apache.jmeter.gui.GuiPackage;
   
   String testPlanFile = GuiPackage.getInstance().getTestPlanFile();
   vars.put("testPlanFile", testPlanFile);
   

3. JMeter’s script name (non-GUI mode)

   import org.apache.jmeter.services.FileServer;
   
   String scriptName = FileServer.getFileServer().getScriptName();
   vars.put("scriptName", scriptName); 
   

If you prefer you can get the same using __Beanshell() function as

${__BeanShell(import org.apache.jmeter.services.FileServer; FileServer.getFileServer().getBaseDir())}

and it will return current base directory where it is called.

source: http://stackoverflow.com/a/28110434/1037754