Step 1: Highlight a tree-folder under which you like to add a new tree-folder.
Step 2: Run New Folder command under Tree menu. Or, Click a right mouse button on the folder to bring up a pop-up menu for Tree menu and then run New Folder command (as shown on right).
Step 3: This generates a new folder name "New Folder" under the folder you highlighted. Edit the name of folder by simply typing a new name.
Step 4: Edit the name of folder by simply typing a new name.
Step 5: Press enter key to accept the changes.