Hi Thom,
I just faced the same problem. And actually is possible to open teamwork projects in Attribute manager.
BIM Server (or BIM Cloud) Save Teamwork projects in the Server or Computer or computer where it is installed. In my office, we installed BIMCloud on my computer so the teamwork files are stored in the following path
This PC > (C:) > Graphisoft > Bim cloud > Server > Projects > (weird name folder) > Backup > Whichever The project you want.
Talk to the IT guy in your office to know where is BIMcloud installed, then you would be able to find your project from Attribute Manager>Import> Browse
I hope this helps you