From the Center for Economic and Policy Research:
The Senate can [demand transparency] by refusing to confirm any nominations until Trump takes the following steps to promote faith that a Trump presidency will not enrich himself and his family:
Releases his tax returns;
Releases a detailed and current financial disclosure that includes beneficial ownership information on all “shell companies” that are part of the Trump Organization;
Follows the advice of the The Wall Street Journal editorial page that “Mr. Trump’s best option is to liquidate his stake in the company” via “a leveraged buyout or an initial public offering";