Select Risk Register on the side menu and choose the risk you wish to link.

Scroll to the bottom of the page and select the Link tab.

Here you'll be able to see any existing links between this risk and another risk or event.

To create a link select Add Link and you'll be taken to a review page, showing all risks and events you have permission to view, and therefore link to.  

The default display option when adding a link are Events.  We can see this from the selection pane on the top right of the page.

We can see from the image below we are viewing all Events and we are hiding those which are closed.

To the very top of the right is the filter option which can help you find a specific risk and/or event you are looking for.

Toggle between Events/Risks and Show closed/Hide closed accordingly to find the right Events and Risks you want to link to this risk.

Use the selection boxes to the right of the Event(s) and/or Risk(s) you wish to link and select Next at the bottom of the page.

Now you'll be asked to provide a reason behind your decision to link the existing Risk to any other Risk(s) and/or Event(s).

Select Complete to finalise your decision and return to the Risk.  You're new links will now appear under the Link tab at the bottom of the page.

To go directly to a linked Event or Risk select the one in question, and to remove the link select the X icon on the right of the Link reason.