To add a question on the particular exam, go to Online Examinations > Online Exam then click on the Question icon present at Action column in the exam list, at the click of this icon Select Question modal will be open.
Now select Subject, Class, Section, and then click on the Search button. After searching, all the questions related to that subject will be visible to you, then select the question you want to add to the exam.
To view the question list of a particular exam, click on the File-Text icon, this will show you all the question lists related to the exam.
Note- If Show me only my question option is Enabled and Teacher Restricted Mode is Disabled then the teacher can view only those questions list which is added by him/her and if Teacher Restricted Mode is Enabled and Show me only my question option is Enabled/Disabled then the teacher can only add/see questions list of that class in which he/she is a class teacher or subject teacher.