On an older machine, I had PMM running and in the MySQL overview, I was able to select All hosts that displayed all of my hosts on a single graph. It was very nice to monitor. Since I installed PMM server on a new server, the 1st host is automatically selected in the hosts list, I can select others, but the All option is not there any linger.
Found the reason, seems this is now moved to the “Cross Servers Graph” dashboard, so all is ok.