If the Feature is Available for Your Facebook Account .you will see Notification bellow The Graph Search box to let you know you can search and view your Old posts. Searching for your olds post is pretty Simple just enter a Keyword or type a Friend name you remember about the post. Keep in mind search results respect your privacy settings, whether it’s info you’ve shared or posts with tags of you that others have shared. After you typed your keyword in the search bar, Graph Search results will show some Results below it. The basic post search option being placed at the very bottom of the list. An easy way to identify a suggestion as being a post search is by the magnifying glass located next to the text. Now click on the Search button and you will be taken to a new screen displaying any and all posts Facebook thinks relevant.
Use this tips to get better Search Results
1. Entering your name or your Friends First name will narrow down the accounts included in the search; that will make it easier to limit the amount of results.
2. Clicking on the settings button in the top-right corner while viewing search results will allow you to change the category of displayed results
3. Sometimes the less you enter the keyword the better. It means Don’t Search for long tail Keywords like “once I went to Disney Land with my Samantha“ that wont give you better Results Simply Search “Disneyland with Samantha”.