A look at the Home Mortgage Disclosure Act data of one of the subprime market’s largest players, CitiFinancial, underscores the challenges facing lenders as they try to cope with new reporting requirements and the need to explain data drawn from a number of disparate business units. The subprime unit of banking giant Citigroup, CitiFinancial was recently accused by advocacy group Inner City Press of misleading regulators and consumers about its origination of high-cost loans. …