Yes I know all that. I just can't list the related files for the one I picked in the 1st listview.
Thats why I need to know how to return the value from the selected item in the 1st listview. When I have that I can use it to select the related files for the one I selected.

heres the code I can for when then form loads. This puts all the files with a bms ext in the 1st listview.
Code:
 private void MapBase_Load(object sender, EventArgs e)
        {
            textBox2.Text = MLHSetting.Default.PlayableMaps;
            string path = textBox2.Text.TrimEnd();
            DirectoryInfo dr = new DirectoryInfo(@path);

            List<string> files = new List<string>();
            int totalfiles = 1;
            foreach (FileInfo file in dr.GetFiles("*.bms"))
            {
                //add each file to the Generic list
                files.Add(file.Name);
                m_Playable.Items.Add(file.Name);
                totalfiles += 1;
            }
            label2.Text = "Total Files : " + totalfiles.ToString();

        }
Then when I select the file name from the list above. The code below will select and add the related files to the 2nd listview
Code:
 private void m_Playable_SelectedIndexChanged(object sender, EventArgs e)
        {
            //string fname = GetFileNameWithoutExtension(m_Playable.SelectedItems);
            //string fname = m_Playable.SelectedItems(m_Playable.SelectedItems);
            ListView.SelectedListViewItemCollection items = m_Playable.SelectedItems;

            label3.Show();
            label3.Text = "Selected File Name : " + items + ".bms";

            m_ListRealted.Items.Clear();

            string path = textBox2.Text;
            DirectoryInfo dr = new DirectoryInfo(@path);

            List<string> relatedfiles = new List<string>();

            foreach (FileInfo related in dr.GetFiles(items + ".*"))
            {

                relatedfiles.Add(related.Name.ToString());

            }
Does that help