Filtering Concat in Subqueries laravel 5

how to make filtering concat in subqueries in laravel 5.

Here is my controller code :

$loan_number    = $request->loan_number;
$borrower       = $request->borrower;
$investors      = $request->investors;

$Query    =  DB::table('loan')->select([ 'loan.loan_number',
                               DB::raw("(SELECT concat(users.firstname,' ',users.lastname) FROM users where borrower.user_id = users.id ) as borrower,loan.amount,loan.created_at as loan_date, (select offer.created_at from offer where offer.investor_id = investor.id order by offer.created_at ASC LIMIT 1) as join_date, 
                              (select users.id from users where investor.user_id = users.id) as investor_id, (select concat(users.firstname,' ',users.lastname) from users where investor.user_id = users.id) AS investor, offer.offer_number,offer.amount, 
                              (SELECT DISTINCT application.status from application where application.stat_id = loan.status) as loan_status ") ])
                    ->leftJoin('offer', function($join) {
                             $join->on('loan.id', '=', 'offer.loan_id');
                      })
                    ->join('borrower', function($join) {
                             $join->on('borrower.id', '=', 'loan.borrower_id');
                      })
                    ->join('investor', function($join) {
                             $join->on('investor.id', '=', 'offer.investor_id');
                      });
           if (!empty($loan_number)){
               $Query = $Query->where('loan.loan_number', 'like', '%'.$loan_number.'%');
           }
           if (!empty($borrower)){
               $Query = $Query->where(I DONT KNOW WHAT SHOULD I DO HERE, HELP PLEASE );
           }
           if (!empty($investors)){
                $Query = $Query->where(I DONT KNOW WHAT SHOULD I DO HERE, HELP PLEASE );
           }
        $result =  $Query->where('loan.status','<>',999)->orderBy('loan.loan_number', 'desc')->paginate($this->paginate)
                         ->appends('loan_number',$loan_number)->appends('borrower',$borrower)->appends('investors',$investors);

        return view('oblagio.investors-investment.index',[ 
            'result'            => $result, 
            'loan_number'       => $loan_number, 
            'borrower'          => $borrower, 
            'investors'         => $investors,
        ]);

to filter $loan_number worked well, but I dont know how to filtering/add "where clause" to filter $borrower & $investors, because they're concat. I've tried to add this code to the code above like this:

 ....DB::raw("(SELECT concat(users.firstname,' ',users.lastname) FROM users where borrower.user_id = users.id and concat(users.firstname,' ',users.lastname) like '%cyber%') as borrower,..........etc.

But the result is : The screenshot also display data that doesn't have value. I just want to display data that only has value. I hope anyone help me here, Thanks in advance.

via arbong