If you are not so familiar with HTML DOM, check this link to learn more...

// Example
echo $html->find("#div1", 0)->children(1)->children(1)->children(2)->id;
// or
echo $html->getElementById("div1")->childNodes(1)->childNodes(1)->childNodes(2)->getAttribute('id');

You can also call methods using the Camel naming conventions.

Method	Description
$e->children( [int $index] ) : mixed	Returns the Nth child object if index is set, otherwise return an array of children.
$e->parent() : element	Returns the parent of element.
$e->first_child() : element	Returns the first child of element, or null if not found.
$e->last_child() : element	Returns the last child of element, or null if not found.
$e->next_sibling() : element	Returns the next sibling of element, or null if not found.
$e->prev_sibling() : element	Returns the previous sibling of element, or null if not found.