LsaLookupSids

[DllImport("Advapi32.dll", SetLastError = true)][return: MarshalAs(UnmanagedType.U4)]
public static extern uint LsaLookupSids(
   IntPtr PolicyHandle,
   uint Count,
   IntPtr Sids,
   out IntPtr ReferencedDomains,
   out IntPtr Names
);

Microsoft documentation: Link