advance payment, retention money and cash flow

dear all

greetings, i am in a problem with puiing advance payment and dedection of this in the monthely payments, cna any one tell me how to show s-cure for the cash flow before and after retention money dedection , or what is possble way to solve about the same subject ,

i ahve seen many answer about the same issue , but i couldnt understant in clear way, can any one have some clear giud for me , with best regards