contract_views.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <data>
        <record id="contract_tree_view" model="ir.ui.view">
            <field name="name">energy_selfconsumption.contract.tree</field>
            <field name="model">contract.contract</field>
            <field name="arch" type="xml">
                <tree string="Contracts">
                    <field name="partner_id" />
                    <field name="supply_point_name" />
                    <field name="code" />
                    <field name="next_period_date_start" />
                    <field name="next_period_date_end" />
                </tree>
            </field>

        </record>
        <record id="contract_search_view" model="ir.ui.view">
            <field name="name">energy_selfconsumption.contract.search</field>
            <field name="model">contract.contract</field>
            <field name="inherit_id" ref="contract.contract_contract_search_view" />
            <field name="arch" type="xml">
                <xpath expr="/search" position="inside">
                    <group expand="1" string="Group By">
                        <filter
              string="Next Period Date Start"
              name="filter_next_period_date_start"
              domain="[]"
              context="{'group_by':'next_period_date_start'}"
            />
                        <filter
              string="Next Period Date End"
              name="filter_next_period_date_end"
              domain="[]"
              context="{'group_by':'next_period_date_end'}"
            />
                    </group>
                </xpath>
            </field>
        </record>


    </data>
</odoo>