src/ArrayContainer.php
public function getNested($keyString, $default = null, $separator = '.')
    {
        $keys = explode($separator, $keyString);
        $data = $this->array;
        foreach ($keys as $key) {
            if(!is_array($data) or !array_key_exists($key, $data)) {
                return $default;
            }
            $data = $data[$key];
        }
        return $data;
    }
public function getNested($keyString, $default = null, $separator = '.')
    {
        $keys = explode($separator, $keyString);
        $data = $this->array;
        foreach ($keys as $key) {
            if(!is_array($data) or !array_key_exists($key, $data)) {
                return $default;
            }
            $data = $data[$key];
        }
        return $data;
    }
Access to value if source array is nested.

@param $keyString
@param null $default default value if no nested keys has been matched
@param string $separator
@return array|mixed|null