Goals/ OKRs are something predominantly used by employees to keep a track of their responsibilities. As a result, the kind of Goals/ OKRs interactions available to Managers are slightly different and more advanced.
For managers, Goals tab is the primary section that will facilitate most of their interactions with their team members. As a manager, you could be a part of more than 1 team; hence, the Goals tab dropdown is how you can navigate between different teams.
Once inside the section (do ensure you're in the right team), you'll find a number of sorting options as well as the three types of views, about which you can read more from here.