Where does “ǵʰostiyo-” come from?

ǵʰostiyo- (Proto-Indo-European) comes from Proto-Indo-European ǵʰes- — hand; take, give in exchange.

Ancestry of “ǵʰostiyo-”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	ǵʰes-	hand; take, give in exchange

ǵʰostiyo- — Etymology, Origin & Word History | Etymology Explorer