Update multiple user details when new user is registered in laravel php

Here is register new user code in php laravel-5.4 mysql

####################code here starts########################3

public function store(Request $request)
{





    $epincheck = $request->epin;

    if (Epin::where('epin', '=', '75656565')->exists()) {



     //   DB::table('epins')->where('epin', $epincheck)->delete();




        $post = new Admin();
        $post->name = $request->name;
        $post->email = $request->email;
        $post->plan = $request->plan;
        $post->epin = $epincheck;
        $post->ref = $request->ref;
        $post->mobile = $request->mobile;
        $post->password = bcrypt($request->password);
        $post->save();





        //other trims


        $referal_user = $request->ref;
        $referal_email = DB::table('admins')->where('mobile', $referal_user)->first();
        $referal_id = $referal_email->id;



        $update_ref_user = Admin::find($referal_id);
        $previous_users_left = $referal_email->user_left;
        $previous_users_right = $referal_email->user_right;
        $direct_referal = $referal_email->direct_referal;
        $list_all_right_user = $referal_email->user_listing_right;
        $list_all_left_user = $referal_email->user_listing_left;
        $left_count = $referal_email->no_user_left;
        $right_count = $referal_email->no_user_right;
        $direct_count = $referal_email->no_direct_referal;

        if(!$previous_users_right && $previous_users_left )
        {
            $update_ref_user->user_right =  $request->email ;
            $update_ref_user->no_user_right =  $right_count+1 ;
            $update_ref_user->user_listing_right =   $request->email . ' , ' . $list_all_right_user ;
            $update_ref_user->save();

            $last_updated_id = $update_ref_user->id;


            $update_up_line = DB::table('admins')->where('id', $last_updated_id);
            $update_up_line_list = $update_up_line->id;

          //  $update_up_line = Admin::find($last_updated_id);

           /* $update_up_line_update->user_listing_right = $request->email;
            $update_up_line-> save();*/



            //looping get referal id -> find referee -> update ;
            //find last  referal id -> find referee -> update ;
            //find referal id -> find referee -> update ;
            //find referal id -> find referee -> update ;
            //find referal id -> find referee -> update ;
            //when there is no ref_no loop ends
            //stop when count ends;






        }

        if(!$previous_users_left)
        {
            $update_ref_user->user_left =  $request->email ;
            $update_ref_user->no_user_left =  $left_count + 1 ;
            $update_ref_user->user_listing_left =  $request->email . ' , ' . $list_all_left_user  ;

            $update_ref_user->save();

        }


        if($previous_users_left && $previous_users_right)
        {
            $update_ref_user->direct_referal = $direct_referal . ' , ' . $request->email ;
            $update_ref_user->no_direct_referal = $direct_count +1 ;

            $update_ref_user->save();

        }
        //sms gatewat
        /*Send SMS using PHP*/



        return redirect('/admin/login');
       // \Session::flash('msg', 'Changes Saved.' );

    }

    else {
        echo "You Have Entered Invalid Pin";
    }






}

###################code ends here ######################

When a new user is registered he inputs reference code in signup form. I want that when a new user is registered with mobile->'123' and reference number '987' then step 1) find "reference number" of new registered user then search "reference number" in "mobile" field of all registered user then add 50% of $200(it is currency)to his income add previous user's name in a database field name="user_under"

step 2) find "reference number" of previous user then search "reference number" in "mobile" field of all registered user then add 30% of $200(it is currency)to his income add previous user's name in a database field name="user_under"

step 3) find "reference number" of previous user then search "reference number" in "mobile" field of all registered user then add 10% of $200(it is currency) to his income and add previous user's name in a database field name="user_under"

step 4) find "reference number" of previous user then search "reference number" in "mobile" field of all registered user then add previous user's name in a database field name="user_under"

******step 4 continues till reference number= null/ no value

I cannot understand how to apply the logic