code: @Override
      public void onViewChild(ModelNode address, String childName) {
          TreeItem rootNode = findTreeItem(tree, address);
          TreeItem childNode = null;
          for(int i=0; i<rootNode.getChildCount(); i++)
          {
              TreeItem candidate = rootNode.getChild(i);
              if(childName.equals(candidate.getText()))
              {
                  childNode = candidate;
                  break;
              }
          }
  
          if(null==childNode)
              throw new IllegalArgumentException("No such child "+ childName + " on "+ address.toString());
  
  
          // deselect previous
          tree.setSelectedItem(null, false);
  
          // select next
          tree.setSelectedItem(childNode, false);
          tree.ensureSelectedItemVisible();
  
          onItemSelected(childNode);
      }
docs: Child selection within editor components (outside left hand tree)
  @param address
  @param childName