partner-contact/partner_contact_department/views/crm_lead_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>

<record model="ir.ui.view" id="crm_case_form_view_leads">
    <field name="name">Add department field</field>
    <field name="model">crm.lead</field>
    <field name="inherit_id" ref="crm.crm_case_form_view_leads"/>
    <field name="arch" type="xml">
        <field name="phone" position="before">
            <field name="department"
                   placeholder="Department"
                   options='{"no_open": True}'/>
        </field>
    </field>
</record>

<record model="ir.ui.view" id="view_crm_case_leads_filter">
    <field name="name">Add department field for searching and grouping</field>
    <field name="model">crm.lead</field>
    <field name="inherit_id" ref="crm.view_crm_case_leads_filter"/>
    <field name="arch" type="xml">
        <field name="section_id" position="after">
            <field name="department"/>
        </field>
        <filter string="Sales Team" position="after">
            <filter string="Department"
                    domain="[]"
                    context="{'group_by': 'department'}"/>
        </filter>
    </field>
</record>

<record model="ir.ui.view" id="crm_case_form_view_oppor">
    <field name="name">Add department field</field>
    <field name="model">crm.lead</field>
    <field name="inherit_id" ref="crm.crm_case_form_view_oppor"/>
    <field name="arch" type="xml">
        <field name="phone" position="before">
            <field name="department"
                   placeholder="Department"
                   options='{"no_open": True}'/>
        </field>
    </field>
</record>

<record model="ir.ui.view" id="view_crm_case_opportunities_filter">
    <field name="name">Add department field for searching and grouping</field>
    <field name="model">crm.lead</field>
    <field name="inherit_id" ref="crm.view_crm_case_opportunities_filter"/>
    <field name="arch" type="xml">
        <field name="section_id" position="after">
            <field name="department"/>
        </field>
        <filter string="Sales Team" position="after">
            <filter string="Department"
                    domain="[]"
                    context="{'group_by': 'department'}"/>
        </filter>
    </field>
</record>

</data>
</openerp>