I want outside assistance with wordpress. The concept is create multioptional navigation in sidebar. Hierarchy is appears like this:

<ul>
<li>First Page
    <ul>
    <li>First SubPage</li>
    <li>Second SubPage
        <ul>
        <li>First Sub-SubPage</li>
        <li>Second Sub-SubPage</li>
        <li>Third Sub-SubPage</li>
        </ul>
    </li>
    </ul>
</li>
<li>Second Page</li>
<li>Third Page
    <ul>
    <li>First SubPage</li>
    <li>Second SubPage
        <ul>
        <li>First Sub-SubPage</li>
        <li>Second Sub-SubPage</li>
        <li>Third Sub-SubPage</li>
        </ul>
    </li>
    </ul>
</li>
</ul>

However i take some features. After i on First Page, i would like see only subpages of the page, not every pages in menu.

The way i can resolve this issue?

Thanks

Take advantage from the function get_pages http://codex.wordpress.org/Function_Reference/get_pages

You should use the next function. Refer to it as within the sidebar with $page_id as <current page id>.

<?php    
function show_child_list($page_id) {
    $child_pages = get_pages( array( 'child_of' => $page_id, 'sort_column' => 'menu_order', 'sort_order' => 'ASC', 'parent' => $page_id) );
    echo '<ul>';
    foreach($child_pages as $child) {
        echo '<li>'.$child->post_title.'</li>';
        show_child_list($child->ID);
    }
    echo '</ul>';
}

Update 1:

Added 'parent' => $page_id attribute in third line, so only first level child are came back.