Merge some child values back into the parent multidimensional array

This is a wonky PHP function I came up with to merge some select values from child arrays into the original. It could really use some help simplifying / making it more elegant.

Is there a built-in method I'm overlooking? array_push didn't work for me because the data needed to be flat.

The problem

What I've got:

array(
    array(
         'nice_value' => 'yup',
         'nice_value2' => 'yup again',
         'ono' => array(
              'nice_value3' => 'yup yup yup',
              'bad value' => 'nope'
          )

    ),
    // array with the same format
    [...]

);

What I need:

array(
    array(
         'nice_value' => 'yup',
         'nice_value2' => 'yup again',
         'nice_value3' => 'yup yup yup'
    ),
    // array with the same format
    [...]

);

The wonky solution

```
// calling in multidimensional array from an api
$lists = $all_lists['data'];
// keys to merge into the parent array, 'key_to_be' => 'key_that_is'
$keys_to_merge = array('members' => 'member_count');
// init the function
$newList = merge_selected_values($lists, $keys_to_merge);

// start writing our function
function merge_selected_values($list, $keys_to_merge) {
// initialize our return array
$newList = array();
// start a counter
$ii = 0;
// begin loop
foreach($list as $key => $value) {
// get first series of array, this is what we want to merge into
if (is_array($value)) {
// loop through these values
foreach ($value as $kk => $vv) {
// find all arrays that are children of our parent array
if (is_array($vv)) {
// loop through these child arrays
foreach ($vv as $stats_key => $stats_value) {
// start looping through the keys that we want to merge
foreach ($keys_to_merge as $keys => $vals) {
// if the key matches
if ($stats_key ==

What's the criteria for deciding which keys to keep?

Check out the array_walk_recursive() function. For example, the following matches any element with a key that starts with "nice_value".

$array = /*your array example*/;
$filtered = array();
array_walk_recursive($array, function($val, $key) use(&$filtered) {
    if (strpos($key, 'nice_value') === 0) {
        $filtered[$key] = $val;
    }
});

StackExchange Code Review Q#45281, answer score: 4