kill two birds with one stone
/ˌkɪl ˌtuː ˌbɜːrdz wɪð ˌwʌn ˈstoʊn/
to accomplish two things with a single action
“Biking to work lets me kill two birds with one stone—exercise and commuting.”
Origin: Ancient proverb, possibly from Ovid's story of Daedalus, achieving two goals with one effort