I’m afraid I don’t have a G5 Plus nor a 2018 Nissan Rogue but let’s see if this link helps:
Depending on your cell phone, the system may automatically download your entire phonebook to the vehicle’s Bluetooth system. If the phonebook does not download automatically, the phonebook can be manually downloaded.
● First, press the MENU button,
● Touch SETTINGS,
● Touch PHONE,
● PHONEBOOK, then
● DOWNLOAD ENTIRE PHONEBOOK
That said, If I were you I would be asking your dealer. You paid a lot of money for that Nissan Rogue and they (IMO), owe it to you to let you know if your phone is compatible with their system.
They (Nissan), makes note that “The transfer procedure may vary depending on the cellular phone. See your cellular phone manufacturer’s Owner’s Manual for details.”
But I don’t see a list of phones their system has issues with.
Your Moto G5 Plus has Bluetooth so that should not be the issue.
But just in case it is, see if this post helps.
Maybe someone in the Community has more advice, but till then I would go back to Nissan and see if you can find out more information from them.