how can i search question with sub-folder when i creating questionnaires

how can i search question with sub-folder when i creating questionnaires

how can i search question with sub-folder when i creating questionnaires. I have created a lot of quesions and group them in different sub folders , but when i creating questionnaires , the sub folders can not be seached.

But there is no sub folders fields when adding the quesions to the questionnaires.