<div>
Blah blah
<div class='myClass'>
  <div>some other div</div>
</div>
</div>

<div>
Blah blah
<div class='myClass'>
  more text
</div>
</div>

<div>
Blah blah
<div class='myClass'>
  more text
</div>
</div>

<div>
Blah blah

</div>

<div>
Blah blah

</div>

<div>
Blah blah

</div>

^  → line beginning
.  → any single character
*  → repeat previous pattern
.*  → any characters as long as possible (greedy)
.*? → any characters as short as possible (non greedy)
$  → line end