Canvas does not have a built-in way to do this.

However, you can segregate the quiz questions into different sections by using the Text (No Question) option to add sections and instructions for the respective sections.

Do note that you cannot randomize questions if you do this.

This approach can also be applied for multi-part questions.

The main question or scenario can be placed in the Section using the Text (No Question) question type.

The parts of the questions will be individual questions after the Section.

Once added, the the section appears as shown below: