Sometimes, when using Git repositories and the Eclipse IDE, we want to access other remote repositories within the one we are currently using.
One example, which I will use as the scenario for the steps below: a team converted existing code and its history to Git from another source-control management tool, with separate repositories for closely related but distinct release points. When they need to make a fix to a past release, on the past release's "hotfix" branch, they want to do as little work as possible to bring that fix into the current cutting-edge "dev" branch of their main repository.
Other writers have offered How-To's for the git command-line steps to do so. What I will do is to show how the setup and configuration can be done within the Eclipse IDE (I used Mars for the screen-shots).