Check Page Level Depth If Condition in WordPress

The code snippet below is handy when you are trying to check if the current page is a parent or a child in a WordPress theme. You can then use the conditional to output different code depending on the page depth it is

<?php
// gets page depth
global $wp_query;
$object = $wp_query->get_queried_object();
$parent_id  = $object->post_parent;
$depth = 0;
while ($parent_id > 0) {
       $page = get_page($parent_id);
       $parent_id = $page->post_parent;
       $depth++;
}
 
// echo $depth;

?>

<?php if ( $depth == 0  ) {
    echo 'page level 0';

}  elseif ( $depth == 1 ) {
    echo 'page level 1';
} else {
    echo 'something else';
}?>

Source: Get the depth of the current page in WordPress