SELECT grou By week

$rows =  AtivosExtrato::select(
                'titulo_id',
                DB::raw('SUM(valor_bruto_atual) AS valor'),
                'data_imports.data_import as created_at',
                DB::raw('WEEK(data_imports.data_import) AS weeknumber')
            )
            ->join('titulos','titulo_id', '=', 'titulos.id' )
            ->join('representantes','representante_id', '=', 'representantes.id' )
            ->join('data_imports','data_import_id', '=', 'data_imports.id' )
            ->where('user_id', Auth::user()->id)
            ->whereIn('ativos_extratos.data_import_id',
            DataImport::Select(DB::raw('max(ID)'))
                ->whereBetween('data_import',  [$request->input('start_date'), $request->input('end_date')])
                ->groupBy(db::raw('Week(data_import)'))            )
                ->whereBetween('data_imports.data_import', [$request->input('start_date'), $request->input('end_date')])
            ->groupBy('titulos.nome_titulo')
            ->groupBy('weeknumber')
            ->orderBy('data_import')
            ->orderBy('titulos.nome_titulo')
            ->get();