Hi, I thought I'd share this solution I kind of stumbled across for unzipping a .zip package when uploading via the Share UI. Hopefully this helps someone searching the forums one day.
Just configure a new business rule in any space. Make sure you leave "apply to subfolders" unchecked because you're only wanting to expand the content into the directory you drop the .zip file in.
–Rule Definition–
When: Items are created or enter this folder
If all criteria are met: Mimetype in cm:content is ZIP
Perform Action: Import to [same space containing rule]
That's all. Of course a script would be better because you could link to the rule in other spaces but this gets the job done.