Shows: inside 内 with one 一 further person 人, who is inside. (cf. third 丙)
Two connected 一 persons are inside, thus both

Left: water 氵, right: grass/plants 艹, pair/both 两 (Two connected 一 persons 人 are inside 内, thus both.)
Water and plants, both can make (your stomach) full.

Left: vehicle 车/車 (車 = cart with axle丨load-area 日 & wheels 二), right: pair, both 两 (Two connected 一 persons 人 are inside 内, thus both.)
You need vehicles, both of them, to be able to count them.

Left: person 亻, right: pair, both 两 (Two connected 一 persons 人 are inside 内, thus both.)
The persons, thus the pair, are both.

Left: eye 目, right: grass/plant 艹; pair, both 两 (Two connected 一 persons 人 are inside 内, thus both.)
(Out of the sight of the) eyes, both are below/inside the grass to conceal sth.