Typically, the way to stay organized in ZenSourcer is to create one ZenSourcer project per Greenhouse Job and add candidates to the project before reaching out.
An added benefit of this is ZenSourcer Project -> Greenhouse Job sync. If you add someone to a ZenSourcer project and then upload them to Greenhouse in the browser extension, ZenSourcer will remember the Greenhouse upload settings you previously selected (e.g. Greenhouse Job, prospect vs candidate, stage) and auto-fill these defaults the next time you add a candidate to a project.
You can also configure a default sequence to a ZenSourcer project to save even more time.