How do you populate workstream/team drop-down when creating a sub-task in Jira

[Shailaja Bhatnagar]

I want to be able to assign workstream/team to a sub-task so that I can organise my Jira board better. But everytime i click on the drop-down list for workstream/team it only has None in its value. How do I create these for my project. For example I want to create one for Requirements Analysis, one for Development, one for Testing, etc.