library/library_checkout/views/library_menu.xml

<odoo>
    <act_window id="action_library_checkout"
        name="Checkouts"
        res_model="library.checkout"
        binding_model="library.checkout"
        view_mode="kanban,tree,form,calendar,activity,graph,pivot" />
    <menuitem id="menu_library_checkout"
        name="Checkout"
        action="action_library_checkout"
        parent="library_app.menu_library" />
</odoo>