Try Get All Actors Of Class | Unreal Engine Documentation to get all AStaticMeshActor (or whatever actor has the mesh you are interested in). Then do another pass over the output array to filter each of these actors based on their static mesh asset.
Try Get All Actors Of Class | Unreal Engine Documentation to get all AStaticMeshActor (or whatever actor has the mesh you are interested in). Then do another pass over the output array to filter each of these actors based on their static mesh asset.