Automatically loggining in to multiple sites

I am setting up a mutlisite network.
On one of my installs I have set up LearnDash (LMS plugin)
I then have customers that have their own install within the network.
I want to add a link within an individuals install (in the dashboard) that links over to the install with LearnDash and logs the user in. So they only have to log in the initial time, not a second time to access the Learndash install site. Is this possible?