Is there any other better UI feature for tree structure to reduce the multilevel nodes.
An alternative that is used sometimes, is a Miller Columns view.
The idea is that the subnodes for the selected item in column a, are shown in column a+1 next to it. A benefit, especially with trees that contain different types of nodes on different levels, is that each column only contains one a single type. That is easy to understand. One downside is that you cannot view and compare multiple branches at the same time. Another is that parent brances move out of view quickly in deeper trees, and that the items which form the ancestors can be at different places in the lists.
An example of this pattern in use, are Apple style file dialogs like these:
For certain types of hierarchies (such as nested text), a control that I call a 'NestView' might be suitable:
This actually evolved from a number of answers given to a question on Programmers.StackExchange:
One alternative - which may not fit your application is the treemap. It is a useful way to display data when the relative size of the nodes is important.
(wikipedia example treemap - in this instance showing changes in waiting times for patients)
This paper on Squarified Treemaps[pdf] is how I learned about the technique. It is quite accessible.
There is also a great jQuery plugin for accomplishing iOS-like drill-down menus: http://filamentgroup.com/lab/jquery_ipod_style_and_flyout_menus/
I would prefer to use smth like iPhone sliding menu for tree structure. Smth like this one http://codecanyon.net/item/jquery-infinite-sliding-menu-plugin/full_screen_preview/164115
I have used a Tag Cloud as a way to organize all the content on my computer for a long time. I have found it to be a efficient way to quickly organize data. The only downside is that you need to make sure your content is tagged.
I use a program for Mac OS X called Leap and it has changed the way I store and access files on my computer.
A minimalistic solution is a "Breadcrumb", like most modern file managers have today. This example is from Wikipedia.
For navigation to the deepest nodes and if you don't need an overall view of the tree but only the lowest nodes, but visibility who they belongs to, then an great alternative that is used by many Car Occasion sites is that it uses combo boxes for navigation down the tree. Look at this: 1. Select car brand in combo box, 2. Select type of car in combo box. 3. Select build year in combo boxes 4. Text free word and then a list is presented with those cars.