There are two starred item lists: local and global. Local starred items are items starred from the conversation you're currently in. Global starred items are items starred from across all conversations. From any group or direct conversation, you can always access the local and global starred item lists.
The local starred items list is found under the local information tab for each conversation. Clicked on the Starred header to expand the section. This will show all starred items in this specific conversation:
The global starred items list is located in the expanded menu at the top right of the room:
You can star a message whenever you find it important. The list of messages you star is accessible only to you; other users can’t see what you star. Starred messages is a great way to keep track of important messages and conveniently access them.
To star and unstar a message, see this helpful article.
If you mouseover a message in the list, a menu will appear. Clicking the hand will cause Connect to automatically jump to the message location in the chat history, so you can easily reference the context.