Search for hashtags became available now in Facebook
Facebook followed by Twitter and Instagram launched a search for the hashtags - a special text labels, starting with # icon.
These special characters are marked messages on the same topic, making it easier to find them and the general orientation of the social network. With hashtags Facebook will allow users to search from the search box, click on the mark in the records of the other broadcast services, and create the publication of lists of records, which are combined with hashtags.
Hashtags on Facebook allow you to add context to a post or indicate that it is part of a larger discussion. When you click on a hashtag in Facebook, you'll see a feed of what other people and Pages are saying about that event or topic.
And how about the privacy settings?
If you are using the Facebook privacy settings to restrict who can see your wall, you are also limiting access to your posts that use hashtags.
Facebook explains this topic:
‘If you have your posts set to friends only (or any other configuration), only those people who are allowed to see it will be able to see your hashtagged post. Clicking on the hashtag will show public posts, as well as posts from your friends who have allowed you to see the post. Privacy settings are respected.’