account-financial-tools/account_loan/security/account_loan_security.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo noupdate="1">
    <record id="account_loan_multi_company_rule" model="ir.rule">
        <field name="name">Account loan multi-company</field>
        <field ref="model_account_loan" name="model_id" />
        <field eval="True" name="global" />
        <field name="domain_force">
            ['|',('company_id','=',False),('company_id','in',company_ids)]
        </field>
    </record>

    <record id="account_loan_line_multi_company_rule" model="ir.rule">
        <field name="name">Account loan line multi-company</field>
        <field ref="model_account_loan_line" name="model_id" />
        <field eval="True" name="global" />
        <field name="domain_force">
            ['|',('company_id','=',False),('company_id','in',company_ids)]
        </field>
    </record>
</odoo>