This moves the separator (indicator) to reflect the position of the clicked label.

MoveIndicator.cs

public void MoveIndicator(object sender)
{

  // Convert the object clicked to a label for easier access to its properties.
  Bunifu.Framework.UI.BunifuCustomLabel clicked_label = (Bunifu.Framework.UI.BunifuCustomLabel)sender;

  // Set the location of the separator (horizontally) to be below the clicked label.
  BunifuSeparator.Location = new Point(clicked_label.Location.X, BunifuSeparator4.Location.Y);

  // Set the width of the separator to be equal to the clicked label's width.
  BunifuSeparator.Width = clicked_label.Width;

  // Set the fore color of the clicked label to be equal to the separator's color.
  clicked_label.ForeColor = Color.FromArgb(132, 171, 204);

}

private void BunifuCustomLabel1_Click(object sender, EventArgs e)
{

  // Call the method and use the "sender" parameter here as the object clicked.
  MoveIndicator(sender);

}