The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.

graphical.target @14.234s
└─multi-user.target @14.233s
  └─nginx.service @13.001s +231ms
    └─network-online.target @12.998s
      └─NetworkManager-wait-online.service @6.140s +6.842s
        └─NetworkManager.service @1.201s +231ms
          └─dbus.socket @1.198s
