Yes there is, at least in winforms
.
Look a little closer, once you add the dot the usual list of items should come up:

ListViewItem item = new ListViewItem("item1");
item.SubItems.Add("subitem1");
Note: To declare an instance you need to reference the class like this:
ListViewItem.ListViewSubItem lvsi = new ListViewItem.ListViewSubItem();
Also note: Sometimes Intellisense stops working; I have to restart VS to bring it back to life..
If however you are targeting WPF
, then you are right: There are no SubItems
in a WPF ListViewItem
. It is a ContentControl
, which can contain whatever you put there, I believe. But I'm no WPF expert. A good book may be best..
System.Windows.Controls.ContentControl
System.Windows.Controls.ListBoxItem
System.Windows.Controls.ListViewItem