There are 3 different types of content you can place in a construct:
You should not, as a general rule, reference constructs into constructs. A construct has a defined level and division assignment. If a construct were to be referenced into another construct, it may have 2 contradicting level and division assignments. However, there are situations where the necessity to do this can occur. For example, when you are checking the correct vertical alignment of a ceiling in the building, you could view a ceiling construct with an overlaid floor plan construct in it. Or, you might want to display alternating versions of a 2 car garage and a 3 car garage within a plan construct. If you encounter a situation where you would need to do this, there are several options that can serve as a work-around:
Which of these options is best for you largely depends on your workflow and the results you want to achieve.