Bootstrap collapse not working on a list view

I have a list view binded to an sqlquery to a ListView. What I want is on click to load data and display for Unitatea 1 but click on Unitatea 2 to hide data for Unitatea 1 and display data only for Unitatea 2.

HTML

code behind

protected void LV1_Click(object sender, EventArgs e)
{
    Button cmd = (Button)sender;
    ListViewItem ObiectivRow = (ListViewItem)cmd.NamingContainer;

    TextBox id = (TextBox)ObiectivRow.FindControl("txtIDOB");
    ListView LV2 = (ListView)ObiectivRow.FindControl("LV2");

    int idob = Convert.ToInt32(id.Text);

    List prm = new List
    {
        new SqlParameter("@IdOB", idob)
    };

    LV2.DataSource = GetDataTable("SELECT DISTINCT IdCL,Cladire FROM tblCladire WHERE IdOB= @IdOB;", prm);
    LV2.DataBind();

}

protected void LV2_Click(object sender, EventArgs e)
{
    Button cmd = (Button)sender;
    ListViewItem CladireRow = (ListViewItem)cmd.NamingContainer;

    TextBox id = (TextBox)CladireRow.FindControl("txtIDCL");
    int idcl = Convert.ToInt32(id.Text);
    ListView LstCamera = (ListView)CladireRow.FindControl("LV3");


    List prm = new List
    {
        new SqlParameter("@IdCL", idcl)
    };

    LstCamera.DataSource = GetDataTable("SELECT DISTINCT IdCA,Camera FROM tblCamera WHERE IdCL =@IdCL;", prm);
    LstCamera.DataBind();

}

an image of the displayed data