Security :: Retrieving Web.sitemap Results Outside Of The Menu?

I understand how web.sitemap works in conjunction with the site's menu in order to make menu/submenu choices visible/invisible depending on the authenticated user's roles.

For example, part of my web.sitemap has the following which defines 3 reports. Then, once users log in, those with "Managers" role can see all 3 reports while those with "Users" role can only see the 1st and the 3rd report:

<siteMapNode url="~/Reports/Reports.aspx" title="Reports" description="Reports" roles="Managers,Users">
<siteMapNode url="~/Reports/LettersReport.aspx" title="Letters Report" description="Letters Report" roles="Managers,Users" />
<siteMapNode url="~/Reports/UserSummaryReport.aspx" title="User Summary Report" description="User Summary Report" roles="Managers" />
<siteMapNode url="~/Reports/LetterSummaryReport.aspx" title="Letter Summary Report" description="Letter Summary Report" roles="Managers,Users" />
</siteMapNode>

How can I retrieve these results outside of the menu process? For example, in one of my web pages, I may need to create a dropdown list which should be populated with the results of the menu process.

How can I make the dropdown list show all 3 items when a manager has logged in but only 1st and 3rd items when a user has logged in?