add a repeatable autopopulate node title select list to custom block
You can use form select options 

put the list of your nodes in to an array and pass them into the form function

function mylist_form($form, &amp;$form_state, $args) {
$mylist = array();
foreach ($args as $node){
$mylist[$node-&gt;nid]= $node-&gt;title;
}

$form['mylist'] = array(
  '#weight' =&gt; '1',
  '#key_type' =&gt; 'associative',
  '#multiple_toggle' =&gt; '1',
  '#type' =&gt; 'select',
  '#options' =&gt; $mylist,
  '#title' =&gt; 'Select nodes',
);
 return $form;
}


after in the block view function you can render the form 

$mylistform = drupal_get_form('mylist_form' , $nodes );