Users cannot search for posts shared on Google+, based on queries because Google+ does not have a search feature. It is quite ironic considering it is a Google product. Just like other features still not available with Google+, we have a third-party developer who has come to the rescue.
Google Plus Search is a search engine for looking up content and profiles on Google+. Note this works only with public content.
I could also use it to search for Google+ profiles and most search queries for even posts do show the profile name of the person who shared the content.
All the posts shared public on Google Reader and Google Buzz are also available which makes it quite useful for bloggers like me to look up social interaction of my blog across Google’s social products.
Google Plus Search also has a Chrome extension and an add-on for Firefox. So until Google brings out a search feature on Google+, use Google Plus Search.
Thanks to Andrew Shen for the tip. Do drop in your comments.