Exemplo Filtros Dinâmicos

gistfile1.py

class CategoriaFather(admin.SimpleListFilter):
    
    title = 'Categorias'
    parameter_name = 'parent__id__exact'
    
    def lookups(self, request, model_admin):
        
        ids = list()
        names = list()
        for cat in Categoria().get_roots():
            ids.append(cat.id)
            count = str(Categoria.objects.filter(parent=cat.id).count())
            names.append(cat.slug+" ("+count+")")
        return zip(ids, names)

    def queryset(self, request, queryset):
        try:
            if self.value():
                return queryset.filter(parent__id__exact=self.value())
            return queryset.filter()
        except:
            pass
class CategoriaAdmin(admin.ModelAdmin):
    list_filter = [CategoriaFather]