At this time, you can only run one Position Tracking campaign per project. However, with a PRO or BUSINESS level account, you can set up multiple targets in the same campaign, allowing you to follow up to 10 locations or devices in one project.
If you want to track even more domains or locations than your single project allows, you'll have to create another project to track the additional information with your account.
If you've created separate Position Tracking campaigns that you want to combine into one project, you can merge your projects from the Devices & Locations tab.
For a full walkthrough on targeting multiple locations in a single Position Tracking campaing, read this blog post.