Odoo Configuration Example

settings.py

class ResConfigSettings(models.TransientModel):
    _inherit = 'res.config.settings'

    your_field = fields.Many2one("module.model",string="Your Field", config_parameter='your_module.your_field')

    def set_values(self):
        super(ResConfigSettings, self).set_values()
        ICPSudo = self.env['ir.config_parameter'].sudo()
        ICPSudo.set_param('your_module.your_field', self.your_field.id)
        
    @api.model
    def get_values(self):
        res = super(ResConfigSettings, self).get_values()
        ICPSudo = self.env['ir.config_parameter'].sudo()
        your_field = ICPSudo.get_param('your_module.your_field')
        
        res.update(
            your_field=your_field.id,
        )
        return res

settings.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <record id="res_config_settings_view_form_firebits" model="ir.ui.view">
        <field name="name">res.config.settings.view.form.inherit.firebits</field>
        <field name="model">res.config.settings</field>
        <field name="priority" eval="25"/>
        <field name="inherit_id" ref="base.res_config_settings_view_form"/>
        <field name="arch" type="xml">
            <xpath expr="//div[hasclass('settings')]" position="inside">
                <div class="app_settings_block" data-string="your_module" string="your_module" data-key="your_module" groups="base.group_erp_manager">
                    <h2>Title of configuration</h2>
                    <div class="row mt16 o_settings_container" name="title_setting_container">
                        <div class="col-12 col-lg-6 o_setting_box">
                            <div class="o_setting_left_pane">
                            </div>
                            <div class="o_setting_right_pane">
                                <label for="_your_field"/>
                                <div class="text-muted">
                                    Your filed description
                                </div>
                                <field name="_your_field"/>
                            </div>
                        </div>
                        <div class="col-12 col-lg-6 o_setting_box">
                            <div class="o_setting_left_pane">
                            </div>
                            <div class="o_setting_right_pane">
                                <label for="_your_field"/>
                                <div class="text-muted">
                                    Your filed description
                                </div>
                                <field name="_your_field"/>
                            </div>
                        </div>
                    </div>
                </div>
            </xpath>
        </field>
    </record>

    <record id="action_your_module_configuration" model="ir.actions.act_window">
        <field name="name">Settings</field>
        <field name="type">ir.actions.act_window</field>
        <field name="res_model">res.config.settings</field>
        <field name="view_mode">form</field>
        <field name="target">inline</field>
        <field name="context">{'module' : 'your_module'}</field>
    </record>

    <menuitem id="menu_your_module_general_settings" name="Settings" parent="config_menu"
        sequence="0" action="action_your_module_configuration" groups="base.group_erp_manager"/>

</odoo>

How can use it for multi company