Go to Components > Select which component you want (segments, metrics, etc) > Click the checkbox next to the item of interest > this will show you the component management bar.
Select share. This will show you the options for sharing with three sections: Organization, Groups, and Users
Remember to scroll down. If are not seeing the groups section populated, check to make sure you have one or more groups set up for the report suite where the component is set up. If you are not seeing anyone in the users section, make sure you have users assigned to that report suite.