How to create 'Search field' with group by feature?

[NulledFL]

I need to create division field(many2one) and need to group them by their parent department wise.good example I got from hr_view.xml.they categorize by 'manager', 'coach', 'department', etc..How to add this feature to my own many2one field.?Please advice..\[code\]<record id="view_employee_filter" model="ir.ui.view"> <field name="name">Employees</field> <field name="model">hr.employee</field> <field name="arch" type="xml"> <search string="Employees"> <field name="name" string="Employees"/> <field name="department_id" /> <field name="category_ids" groups="base.group_hr_user"/> <group expand="0" string="Group By..."> <filter string="Manager" icon="terp-personal" domain="[]" context="{'group_by':'parent_id'}"/> <filter string="Coach" icon="terp-personal" domain="[]" context="{'group_by':'coach_id'}"/> <filter string="Department" icon="terp-personal+" domain="[]" context="{'group_by':'department_id'}"/> <filter string="Job" icon="terp-gtk-select-all" domain="[]" context="{'group_by':'job_id'}"/> <filter string="Company" icon="terp-go-home" domain="[]" context="{'group_by':'company_id'}" groups="base.group_multi_company"/> </group> </search> </field> </record>\[/code\]