Valvoline Maxlife full-synthetic ATF is compatible with NissanMatic "J" and "S" ATF; I have over 200,000 combined miles using Valvoline Maxlife in my two R51 Pathys and a lot of other people use it, too. Castrol Transmax Mulit-import ATF is also compatible (Castrol makes the transmission fluid for Nissan), among other synthetics. I like the Valvoline because I can get it in a 1-gallon container (which is the typical amount needed for a drain and fill) at Walmart for $18:
https://www.walmart.com/ip/Valvoline-Ma ... n/15125768
There is no filter to change inside of the transmission. There is a screen, but it's not meant to be serviced, so there's no point in dropping the transmission pan. It has a drain plug and the gasket is the same as the engine oil pan drain plug gasket: Nissan 11026-01M02. Torque spec on the drain pan bolt is 25 ft/lbs.