Sorry if anyone else has already posted something similar but I did search and didnt see anything
I helped someone out with this in a thread today/yesterday and thought I'd post it here for others to use in the future if they want to do a similar thing.
You can use this to find a list of all of the members of any group in AD. You will need to add a reference to System.DirectoryServices first though.
Dim GroupSearcher As New DirectorySearcher
'Change the OU path, domain and domain admin details
Dim GroupSearchRoot As New DirectoryEntry("LDAP://OU=YourGroupsOU,DC=yourdomainname,DC=com", "Your_Domain_Admin", "Admin_Password")
.SearchRoot = GroupSearchRoot
.Filter = "(&(ObjectClass=Group)(CN=YourGroupName))" '<<< Change the Group name here
Dim Members As Object = GroupSearcher.FindOne.GetDirectoryEntry.Invoke("Members", Nothing) '<<< Get members
For Each Member As Object In CType(Members, IEnumerable) '<<< loop through members
Dim CurrentMember As New DirectoryEntry(Member) '<<< Get directoryentry for user
ListBox1.Items.Add(CurrentMember.Name.Remove(0, 3)) '<<< Add user's CN(common name) to listbox
As you can see in my example, I am using a listbox named Listbox1 to display all of the user's names. If you dont want to do that then just remove that line and use the directoryentry object for each user to get whatever attributes you want etc
Hope it helps someone out