In OpenERP first, create a custom module and then inherits the account.payment object in your own module like module name test.

Follow these steps given below

Step1- First create the __init__.py file in your test module and use this code given below,

import test

Step2- Then create another file like:  __openerp__.py file in your test module and use this code shown in below

{
    "name": "Test",
    "version": "1.0",
    "author": "sachin singh",
    "description" : "this module basically for show all amount when customer payment is full then all amount show in your fields",
    "depends": ["base","account"],
    "category" : "Generic Modules/Others",
    "init_xml": [],
    "update_xml": ["test.xml"],
    "active": False,
    "installable": True,
 }

Step3- Now create another file like: test.py file in your test module and then create a nnew field in this file, use this code shown below,

from openerp.osv import osv, fields
class test(osv.Model):
    _name = 'test'
    invoice_total_paid1 = fields.Text(string='Total payment', required=True)
   
test()

class account_payment(osv.Model):
    _inherit = 'account.payment'
    
    @api.multi
    def post(self):
        super(account_payment,self).post()
        for inv in self.invoice_ids:
            inv_origin = inv.origin
            
        payment_ids = self.search([])
        pay_rec_list = []
        for pay in payment_ids:
            for inv in pay.invoice_ids:
                if inv_origin == inv.origin:
                    pay_rec_list.append(pay.id)
        
        cur_payment_ids = self.search([('id','in',pay_rec_list)])
        total = 0
        for p in cur_payment_ids:
            total += p.amount
        rent_rec_id = self.pool.get('rent.order').search(self.env.cr,self.env.uid,[('reference','=',inv_origin)])
        self.pool.get('rent.order').write(self.env.cr,self.env.uid,rent_rec_id,{'invoice_total_paid1':total})

Step4- Last step is to create the test.xml file in your own module and use this code shown below

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
 <!--  Here is a rent order tree view -->   
      <record model="ir.ui.view" id="rent_order_tree_view">
            <field name="name">test.order.tree.view</field>
            <field name="model">test</field>
            <field name="type">tree</field>
            <field name="arch" type="xml">
                <tree string="test Orders">
                    <field name="invoice_total_paid1"/>
                </tree>
            </field>
        </record>
 <record model="ir.ui.view" id="rent_order_form_view">
            <field name="name">test.order.form.view</field>
            <field name="model">test</field>
            <field name="type">form</field>
            <field name="arch" type="xml">
                <form string="test Order">
                    <group colspan="4" col="6">
                       <group>
                        <field name="invoice_total_paid1"/>
                        </group>
                    </group>
                </form>
           </field>
   </record>


 <record model="ir.actions.act_window" id="rent_action_form">
            <field name="name">test Order</field>
            <field name="res_model">test</field>
            <field name="view_type">form</field>
            <field name="view_mode">tree,form,calendar</field>
            <field name="usage">menu</field>
            <field name="search_view_id" ref="rent_order_search_view"/>
        </record>
        <menuitem id="rent_order_menu" parent="base.menu_sales" groups="base.group_sale_salesman"
                  name="Tests" action="rent_action_form"/>

</data>
</openerp>