NOTE: Before updating any product you should first make a backup of your site files and your database.
To update a theme navigate to Dashboard > Appearance > Themes. Any theme with automatic update integration will have a red-orange bar at the top of the theme with the words "Update Available". Clicking on the red bar will bring you to the update screen.
After the update screen appears simply click the "Update Now" text shown below.
Upon success you will see a screen similar to the one below.
If the integrated automatic update fails for any reason you will need to update manually. Start by logging into BuddyBoss.com and navigating your your "My Account" area: https://www.buddyboss.com/my-account/ and download the latest version.
Extract the contents of the zip file to a known location on your computer. NOTE: Don't simply press ok on all the windows without knowing the file location.
After extraction you will need to log into your websites FTP and copy the extracted theme files to the following location: /wp-content/themes/ Overwrite all files. That's all, you are done updating your theme!