Hi Dorothy,
Thanks for contacting me here.
To remove the sidebar, you may need to try a couple of things. One is to use a page for the “Business Directory” itself that is a full-width page. That’s under Pages->All Pages. Edit the page and change the page template.
If that doesn’t do it, your theme may be placing sidebars on the listing page because of the page type. You can check under Appearance->Themes and see if there’s a setting to control what is visible on the listing page for BD (some themes allow for widget-specific settings on pages, but not all).
Failing that, if you can’t get either of those to work, you can use our “compatibility mode” by going under Directory Admin->Manage Options, General tab and checking “Disabled Advanced CPT Integration” and see if that helps.