contract/contract_forecast/security/contract_line_forecast_period.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2019 ACSONE SA/NV
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->

<odoo>

    <record model="ir.model.access" id="contract_line_forecast_period_user_access">
        <field name="name">contract.line.forecast.period user access</field>
        <field name="model_id" ref="model_contract_line_forecast_period"/>
        <field name="group_id" ref="base.group_user"/>
        <field name="perm_read" eval="1"/>
        <field name="perm_create" eval="1"/>
        <field name="perm_write" eval="1"/>
        <field name="perm_unlink" eval="1"/>
    </record>

    <record id="contract_line_forecast_period_comp_rule" model="ir.rule">
        <field name="name">Forecast multi company rule</field>
        <field name="model_id" ref="model_contract_line_forecast_period"/>
        <field name="domain_force">
            ['|',('company_id','=',False),('company_id','child_of',[user.company_id.id])]
        </field>
    </record>

</odoo>