Every time you search for something on Facebook, your searches get stored in your Activity Log. Because I know it's not that easy even for the experienced computer user to find the Facebook's Search History easily and requires too much clicking, here's how to view it or clear it real fast.
Log into your fb account, Copy (Ctrl+C) the link below and paste it (Ctrl+V) in your browser. Just don't forget to add your username instead 'Your FB Username'.
https://www.facebook.com/YOUR FB USERNAME/allactivity?privacy_source=activity_log&log_filter=search
This link will take you directly to your FB Search History where you can view it or clear it.
You can also bookmark the link for a later use.