Quite likely it was Bachiv, Ukraine (Baczów in Polish language) a village southeastern of Lviv. However you should not assume it is this village without further double-checking (there could be other villages of the same name in the same region which are not searchable in OSM).
It is a regular occurence to have place names ending in -ów in Polish and -iv in Ukrainian language, such as : Lwów/Lviv , Kraków/Krakiv, Kjów/Kiev, and so on so forth. Endings in -iw in Polish languge are extremely unlikely.
This village was part of Poland before 1945. You can't see it on this map of pre-war poland because the village isn't large enough, but you can see both larger villages : Rohatyn and Przemyślany - both are also visible on OSM and have similar names in Ukrainian today so this confirms this area was part of Poland before 1945.
Note that another locality in this region, marked Firlejów on the old map, can't be found on a modern map, and after some investigagion this is because the village is today named Lypivka in Ukrainian. So it's possible for villages in this area to have changed their name completely. This also means it's possible for another Baczów village to have been renamed completely and not be foundable anymore without detailed investigation.