For further simple xpath usage
<field name="occupation_id" placeholder="Student/Employee/Other" domain="[('domain','=', 'occupation')]" attrs="{'required': [('is_company','=', False)]}"/>
</group>
</group>
<field name="occupation_id" placeholder="Student/Employee/Other" domain="[('domain','=', 'occupation')]" attrs="{'required': [('is_company','=', False)]}"/>
</group>
</group>
+ <notebook name="Volunteer activities">
<page string="Volunteer activities" attrs="{'invisible': [('is_company','=',True)]}">
<label string="Want to be volunteer in ..."/>
<field name="volunteer_ids" domain="[('domain','=', 'volunteer')]" string="Want to be volunteer in ..."/>
<page string="Volunteer activities" attrs="{'invisible': [('is_company','=',True)]}">
<label string="Want to be volunteer in ..."/>
<field name="volunteer_ids" domain="[('domain','=', 'volunteer')]" string="Want to be volunteer in ..."/>