If you want to access your bins at an older stage of your editing, this is what you can do:
Hide Avid. Use the finder window to navigate to the Avid attic folder “Macintosh HD/Users/Shared/AvidMediaComposer/Avid Attic”*
*If you're working off the Nexis, the attic folder is in your shared space called "Unity Attic."
Double click on the Avid Attic Folder, then click on specific project folder you are restoring. Double click the Bins folder.
Select View - "as List" if the Avid Attic folder is not already in List view. The bin folder will display the backup bin files and their creation dates.
Shift+click the files you want to restore, and Option+drag the selected backup files to the desktop. This makes a copy of the files, leaving the original files in the Avid attic folder.
Open up avid and close all your bins. The Avid system does not allow a bin and a copy of a bin to be opened at the same time. You must keep all other bins closed, and open the backup bins one at a time.
Double click the restored bin file on your desktop. Avid will open the bin file and place it under a project folder called “Other Bins.”
Create a new bin for your restored sequences. Select the material you want to keep from the backup bin, and drag the files into the new bin. (Repeat steps for any other backup bins you copied to the desktop.)
Select and delete the backup bins in the Other Bins folder.
Drag the backup bin files on the desktop to the Trash.