So when you are typing out your content for you hub, you will see you will a toolbar with various icons above the area where you type in your text. Near the right hand side, you will see something that looks like a chain and a broken chain icons.
1) So to do it, you must first type in your text (ie I want to use this as a link) and then highlight the text you want the link to go on....
2) Press the chain icon
3) A window will load up and look for the drop-down list box that says Quick Link to Hub
4) Select the hub you want to link to
5) Press the Insert button
You will notice your text change color to blue or if you move your mouse over the link that you created, it will put an underline on the text that has the link.