I have a model Transaction with a ForeignKey to another model (TransactionState) on state field. So in admin.py I have:
class TransactionAdmin(admin.ModelAdmin):
...
list_filter = ('state', )
...
In TransactionState I have records like "paid", "unpaid", "delivered", "canceled", Etc. and it works fine but I want to be able to filter using checkboxes to allow multiple selection like "paid" OR "delivered". It's possible?