Immediately below a post, click the Share link.

This opens the Share Activity dialog.

In the Share list, select one of these options:

• On your own feed This lets you share the article on your feed.
• On someone else's feed This lets you share the article on the feeds of the registered users you specify. If you select this option, type the user name(s) in the People field.
• In a group This lets you share the article in a group feed. If you select this option, type the group name(s) in the Group field.