1 - Access the website below:
https://mapgenie.io/witcher-3/maps/velen-novigrad2 - Filter by "Monster Nest" location only.
3 - All available monster nests will be indicated on the interactive map.
4 - Remember to craft enough bombs to destroy at least 10 monster nests.
5 - Choose the location where you want to start and have a good hunt.
Just in case, here's a video tutorial on the achievement. Credits are from the Channel "AlienTenno"