In your view click the down arrow next to the view name.
Then select Customize View
Click on Set rules for file display
In the rules section you the drop downs to select Filename (Path) - Is not
Then type the path to the directories that the Itunes files are. You can add as many rules as you want.
This is just one way of doing it.
You could set up a new view and only show files from your Itunes directory and then tag all those files with a custom field (you could create a field called Itunes) and put Yes in that field for your Itunes files, and then use rules to not show files that are yes in your field.
You could possibly clear your library and only import the directories you really want in the libray too. But keeping all your files in the library is a better option I think.
There are many ways to accomplish what you want..
Ken