Brief requirements are part of our paid subscription plans.
Assigning assignments follows the same approach as assigning usages.
As soon as a project contains a brief, the Usage palette updates to show the Requirements:
If you've used Space groups, you can expand and contract the groups to easily navigate the requirements listing.
You can also assign Requirements to Planning Zones and Space with their Settings.
Select the element(s) and open the Context settings:
Again, with Space Groups, the lists become easier to navigate: