Ember Js and Sails js AND clause in controller

I'm working on a project with Ember.js and Sails.js now i'm having an issue in my controller,

i want to run a computed query and use "AND" clause but i don't know how to do it, i tried to google it but had no luck

here is my controller

selectedDepartment: Ember.computed(function (){
  return this.get('store').query('service', {
    where : {
      department : this.get('department.id'),
      isPublic : true
      }
   })
})

It's getting me crazy i mean what is wrong here ?