How to change privacy settings for shared posts in Facebook for Android

First, make sure you have the most recent version of Facebook for Android. Just because you've done all updates from the Google Play Store doesn't necessarily mean that you're using the latest version. Many mobile app updates are done with a staged rollout, which can be quite annoying if you're not in the first group. The easiest way to check your current version is to go into the Application Manager (Settings > Applications) and find Facebook in the list. When you tap it, the version number will be displayed in the top area of the screen.

After a post is finished updating to Facebook, just tap on the three dots in the top-right corner and select Edit Privacy. Next, select the audience you want to share the post with. Now the post will be available only to the people you selected. Via (cnet.com)