Indeed all entities have to be in the same package.
Normally you use a structure like
com.example.myapp.data
Where you put everything for managing your database, especially your entity classes. Inside you can let greendao create a dao package where it will put everything needed to access your data (base).
Of course you can enforce your naning schema by making multiple sxhemas in greendao. But the schemas will be independent: They won't use the same database and you won't be able to link them together with toOne ()
for example.
If you still want to use your naming schema you can generate everything to an intermediate package and move them to your desired packages manually. But you would have to repeat this upon every change to your database schema, which is more often than one may think at first.