I'm afraid I don't quite understand your question.
Are you looking for a tool to look at Photoshop thumbnails of Photoshop files? If so, your best bet is to use Bridge, which installs with Photoshop and which is found under the File menu. Click File > Browse in Bridge and I believe you will have what you're looking for.
If I've misunderstood your question, please let me know and clarify so I can help you.