Today I implemented full Folder Navigation in Office365
I found this sample code from Office Developer Center by mr. Sohel Rana and it worked like a charm.
The guick step by step guide:
1: Download files (and unzip .. døh..)
2: Navigate to Site settings –> SiteCollections MasterPage Gallery –> and upload New Document – Javascipt Display Template
3: In form upload the foldernavigation.js extracted file from step1
and fill inn *data accordingly.
4: Add ~siteCollection/_catalogs/masterpage/FolderNavigation.js in the JS Link section on any web-part in any subsite in your SiteCollection
Now you got that nice breadcrumb view for Folder Navigation