Pretty Theme Files will organize your theme files in editing panel.
It lists theme main files first, with sub-listing of every other file related to main files.
This plugin will make so much easier to deal with themes that have many files.
1. Upload the whole plugin folder to your /wp-content/plugins/ folder.
2. Go to the Plugins page and activate the plugin.
3. When you visit theme editor the files will be organized now
You can also visit my other WordPress Plugins.