nelhage/reptyr: Reparent a running program to a new terminal - GitHub
Display your running background jobs with jobs -l, this should look like this: [1]+ 4711 Stopped (signal) top (The -l in jobs -l makes sure you'll get the PID) Disown the jobs from the current parent with disown top. After that, jobs will not show the job any more, but ps -a will. Start your terminal multiplexer of choice, e.g. tmux