How to implement a field for selecting a position in a user profile?

Question

1C-Bitrix

Hello! Tell me how to implement a field for selecting a position in a user profile?
There is a list of departments and positions, and in the personal account the user must select a position:
1. RESEARCH STAFF
1.1. Intern-researcher
1.2. Junior Researcher
....
2. TRAINING STAFF
2.1. Faculty dispatcher
2.2. Training Master
....
While such an option. Create an infoblock type "reference books" and place the "positions list" infoblock into it. Accordingly, the sections of the infoblock will be a list of departments, and the elements will be a list of positions. I create a new field with the type binding to infoblock elements, but then it displays a complete list without breaking it into sections. The fact is that there are more than 100 posts and it is not convenient to choose from the list without breaking it down into sections. How to display all this in your personal account is also not clear.

Answer 1

Ideally, create a custom type of custom field based on binding to IB elements blog.yasla.net/2012/08/1.html
Copy it and change the output and editing templates.
Well, or in the component that displays the user's profile, cut it and insert the desired output there for this particular field.
Method 1 is more correct, and will create fewer problems for the future.
2 is faster.