Need help with tail light assembly 2003 nissan frontier

I got pulled over for the previous owners not ok tail light assembly, so I got a
new pair to install. They look different so I am unsure how the bulbs go in.
The old ones are 3 sections, top red plastic, middle red plastic, bottom white
plastic lenses. They function as top brake and tail light, middle turn signal,
bottom backup. Currently the bulbs are top clear, middle amber, bottom clear
bulb.  The new proper tail light assembly is 3 sections, top is red plastic,
middle is white plastic, and bottom is red plastic. So I dont know which bulbs
go where because the white sections are in different places and I cant find
any info online about what is the function of the new top, new white middle
and new red bottom. Any help much appreciated! emily