I am working on a sharepoint server 2013 on-premise. currently I have 3 site collections. And on some site collections I have 2 levels of sub-sites.
Now currently we depend on the left side navigation (Quick launch links) for navigating between the site collections and their sub-sites. But the problem with the current navigation is that you can not know where in the hierarchy the current site or the current list is in. Now on most web applications this can be achieved using a breadcrumb navigation.. such as
Home>> Sitecollection Name >> subsite Name>> List Name