What was the verdict
I brought the Murano to the dealer per NissanAssit agent suggestion. The tech inspected the oil leak and determined the leak is from the transfer case. The assistant service manager told me the service charge was $1800. I could not believe the diagnosis and the service manger offered me to inspect the leak with a senior tech. I pointed out that the leak is apparently under the CVT oil pan and the the transfer case area is clean. The assistant service manager had good attitude and agreed to call Nissan asking for service under CVT warranty.
However, the general manager of the dealer indicated that Nissan would only accept the coverage with a through diagnosis and I needed to authorize the dealer to conduct a $200 diagnosis involving dye leak detection and taking some parts apart. After the through diagnosis, the dealer told me that the oil leak is 70% from the CVT and 30% from the transfer case. I will get a new CVT under the warranty, but need to pay ~$700, labor and parts for replacing the seals of the transfer case.
I am disappointed about the CVT performance, but happy that my observation was right and Nissan will take care of the CVT. I could be fooled if simply accepted the initial inspection and paid the $1800 for the transfer case service.