You need to wrap all your site map nodes inside one site map node. i.e Your sitemap file should look like this:
<sitemap>
<sitemap>
<sitemapnode url="authendicate.aspx" title="Home">
<sitemapnode title="Employee Manage" description="Managing Employee details">
<sitemapnode>
url="NewEmployeeDetails.aspx"
title="New Employee"
description="new employee details" />
<sitemapnode>
url="EmployeeDetails.aspx"
title="EmployeeDetails"
description="employee details" />
</sitemapnode>
<sitemapnode>
url="EmployeeDetails.aspx"
title="Activation"
description="Activate and deactivate employee" />
</sitemapnode>
<sitemapnode title="Leave Manage" description="Managing Leave details">
<sitemapnode>
url="ApplyForLeave.aspx"
title="ApplyForLeave"
description="Apply For Leave" />
<sitemapnode>
url="ViewLeaveRequest.aspx"
title="ViewLeaveRequest"
description="View Leave Request" />
</sitemapnode>
</sitemapnode></sitemapnode></sitemapnode></sitemapnode></sitemapnode></sitemap>
</sitemap>
else you can also try
this[
^] solution.
Hope this helps.
All the best.