odoo-contact-addons/partner_contact_majority/views/res_partner.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl.html). -->
<odoo>

  <record id="personal_information_form_inherit" model="ir.ui.view">
    <field name="name">res.partner.form.inherit.majority</field>
    <field name="model">res.partner</field>
    <field name="inherit_id" ref="partner_contact_personal_information_page.personal_information" />
    <field name="priority">18</field>
    <field name="arch" type="xml">
      <group name="personal_information_col1" position="inside">
        <field name="nationality_id" options="{'no_create':1, 'no_open':1}" />
      </group>
      <field name="age" position="after">
        <field name="majority_date" attrs="{'invisible':[('is_major','=',True)]}" />
        <field name="emancipation_date" attrs="{'invisible':[('is_emancipated','=',False)]}" />
        <field name="is_major" invisible="1" />
        <label for="legal_status" />
        <div class="o_row" attrs="{'invisible':[('is_major','=',True)]}">
          <field name="legal_status" nolabel="1" class="oe_inline" />
          <span class="oe_inline">still for</span>
          <field name="majority_years" nolabel="1" class="oe_inline" />
          <span class="oe_inline">years</span>
        </div>
        <div class="o_row" attrs="{'invisible':[('is_major','=',False)]}">
          <field name="legal_status" nolabel="1" class="oe_inline" />
          <span class="oe_inline">for</span>
          <field name="majority_years" nolabel="1" class="oe_inline" />
          <span class="oe_inline">years</span>
        </div>
        <field name="is_emancipated" invisible="1" />
      </field>
    </field>
  </record>

</odoo>