How to display sections and elements with certain infoblock properties?

Question

CMS

Hello!
I have been working with Bitrix recently, so I apologize for the stupid question.
Yes, I have read the documentation. Yes, I used google.
There is such a structure
Section 1
Subsection 1
Element 1
Element 2
Subsection 2
Element 1
Element 2
Section 1
Subsection 1
Element 1
Element 2
Subsection 2
Element 1
Element 2
and so on.
You need to display all sections, subsections and elements. Moreover, elements with certain properties (there is no SEO description).
Thanks in advance.