  A large population of intermediate-separation binaries, consisting of a
main-sequence (MS) star and a white dwarf (WD), has recently emerged from
Gaia's third data release (DR3), posing challenges to current models of binary
evolution. Here we examine the $s$-process element abundances in these systems
using data from GALAH DR3. Following refined sample analysis with parameter
estimates based on GALAH spectra, we find a distinct locus where enhanced
$s$-process elements depend on both the WD mass and metallicity, consistent
with loci identified in previous asymptotic giant branch (AGB) nucleosynthesis
studies with higher $s$-process yields. Notably, these enhanced abundances show
no correlation with the systems' orbital parameters, supporting a history of
accretion in intermediate-separation MS+WD systems. Consequently, our results
form a direct observational evidence of a connection between AGB masses and
$s$-process yields. We conclude by showing that the GALAH DR3 survey includes
numerous Ba dwarf stars, within and beyond the mass range covered in our
current sample, which can further elucidate $s$-process element distributions
in MS+WD binaries.
