GTAV\mods\update\x64\dlcpacks\patchday2ng\dlc.rpf\x64\levels\gta5\_hills\cityhills_01\ch1_occl.rpf\
if this does not fix occlusion issues, install here-
GTAV\mods\x64n.rpf\levels\gta5\_hills\cityhills_01\ch1_occl.rpf\