partner-contact/partner_changeset/views/res_partner_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="res_partner_view_buttons" model="ir.ui.view">
      <field name="name">res.partner.view.buttons</field>
      <field name="model">res.partner</field>
      <field name="inherit_id" ref="base.view_partner_form" />
      <field name="priority" eval="18"/>
      <field name="groups_id" eval="[(4, ref('partner_changeset.group_changeset_user'))]"/>
      <field name="arch" type="xml">
        <xpath expr="//div[@name='button_box']" position="inside">
          <button class="oe_inline oe_stat_button"
            type="action"
            name="%(partner_changeset.action_res_partner_changeset_view)d"
            context="{'search_default_draft': 1, 'search_default_partner_id': active_id}"
            icon="fa-code-fork">
            <field string="Changes"
              name="count_pending_changesets"
              widget="statinfo"/>
          </button>
        </xpath>
      </field>
    </record>

    <record id="view_res_partner_filter" model="ir.ui.view">
      <field name="name">res.partner.select</field>
      <field name="model">res.partner</field>
      <field name="inherit_id" ref="base.view_res_partner_filter" />
      <field name="arch" type="xml">
        <filter name="customer" position="after">
          <separator/>
          <filter string="Pending Changesets"
            name="pending_changesets"
            domain="[('count_pending_changesets', '>', 0)]"/>
        </filter>
      </field>
    </record>
</odoo>