Laravel 的查询条件怎么支持传递字符串，进行链式操作。$where="where ('created_at', '>', Carbon::today ())";

public function getTodayRegister()
    {
        $where="where('created_at', '>', Carbon::today())";
        return $this->getCount($where);
    }
    public function getCount($where)
    {
        if ($data=request()->only('field')) {
            User::Organization()->OrgAjaxRequest()->$where->get()->filter(
                function ($v, $k) use($data){
                    if ($v->extra) {
                        foreach ($v->extra as $k1 => $v1) {
                            if ($k1 == 'field') {
                                if (array_intersect($v1, $data['field'])) {
                                    return true;
                                } else {
                                    return false;
                                }
                            }
                        }
                    } else {
                        return false;
                    }
                }
            )->count();
        }

        return User::Organization()->OrgAjaxRequest()->$where->get()-count();
    }

$where="where('created_at', '>', Carbon::today())";传递进来之后，不能解析

User::Organization()->OrgAjaxRequest()->$where->get()-count();

报错

Undefined property: October\Rain\Database\Builder::$where

请问是否有这样调用的可能