Retrieve Information off Older Time Machine Drive

I have my MacBook Pro backed up to 2TB HD. I have backup drives from other MacBooks. When I plug a HD from another MacBook it shows up on the desktop. Click and Backups.backupdb ... Name of Folder .... List of dates... So basically what would be the best way to get information off an older Time Machine Backup Drive? What if anything needs to be changed to read an older Time Machine Drive?