I have created a sales team with following team hierarchy:

• Sales Manager
  • Sales Person
    • Sales & Quotations, Leads, customers 

I want that the Sales Manager can see all the customers of his/her team. Same functionality I wanted for the leads and for that I have applied this domain filter ['|', ('section_id','=',user.default_section_id.id),('section_id','=',False)] which worked perfectly. And for customers, I am applying this domain filter [('user_id.section_id', '=', user.default_section_id,id)], but unfortunately I did'nt get success. I have applied numerous different domains but all are failed. Please help me out of this problem.