The Campaigns widget in the Now dashboard allows you to see the top campaigns on your website in real-time. Specifically it shows the
utm_campaign (campaign name) found in the referral URLs that visitors currently on your site came from.
If you can't see the Campaign widget then press the e key on your dashboard to edit the layout of your widgets.
Setup campaign tracking
When you run campaigns, you provide links to your website where you hope to send visitors. The industry standard method of tracking these links is to use UTM parameters.