Unit test to the solution:

@Test
  public void run() throws TeamRepositoryException {


    TeamPlatform.startup();
    try {


      String repositoryURI = "" ;    //Your Repository Here
      String userId = "" ;                 //Your username Here
      String password = " " ;            //Your Password

     String memberUser = "" ;               // The user for whom you want the project areas to be listed

      ITeamRepository teamRepository = TeamPlatform.getTeamRepositoryService().getTeamRepository(repositoryURI);
      teamRepository.registerLoginHandler(new LoginHandler(userId, password));
      teamRepository.login(null);

      System.out.println("Logged in as: " + teamRepository.loggedInContributor().getName());

      if (projectAreaName == null) {
        // For all project areas
        IProcessItemService itemService =
            (IProcessItemService) teamRepository.getClientLibrary(IProcessItemService.class);
        List pAreas = itemService.findAllProjectAreas(null, null);
        for (Iterator iterator = pAreas.iterator(); iterator.hasNext();) {
          IProjectArea projectArea = (IProjectArea) iterator.next();
        
          IContributor user = teamRepository.contributorManager().fetchContributorByUserId(memberUser , null);

          if (projectArea.hasMember(user)) {
            System.out.println(projectArea.getName());
          }

        }
      }

      teamRepository.logout();

    }
    catch (TeamRepositoryException x) {
      x.printStackTrace();
    }
    finally {
      TeamPlatform.shutdown();
    }

  }