How to make a menu (on Bitrix) with subsections that are displayed only when you are in the section?

Question

1C-Bitrix

Good evening
Please tell me
Task: Make a menu with subsections that are opened only when you are in the section.
Example:
Category 1
Category 2 ← (if we are here, subcategories are open)
→ Subcategory 1
→ Subcategory 2
→ Subcategory 3
Category 3
Category 4
Category 1
Category 2
Category 3
Category 4 ← (if we are here, subcategories are open)
→ Subcategory 1
→ Subcategory 2
→ Subcategory 3

Answer 1

The question is too general. Specify what doesn't work.
If you also answer generally, then such a menu is implemented on the basis of a standard component in a standard template. You just need to make the submenu of the active item displayed, for example, set in css dispaly: none; for submenu blocks and display: block; for a submenu block whose parent has the class you assign to the active menu item.
It seems that such a layout is in one of the standard menu templates - look at the standard templates. Although I may be wrong and no longer.