Multi-row mega menu

Excuse me - I didn't understand how to make the line.
I made two points of the menu 1abc and 4abc.
I am hide title at 1abc, 4abc and they are have children.
But the horizontal line didn't appear.

I found such solution: I made the module with html code <hr>.
Then I added one more point of the menu between 1abc and 4abc. And I inserted the module with the <hr> code into this point of the menu. But it is somehow too difficult. It is possible to make simpler?

Hi alexvolhov!
I'm sorry, I forgot to tell you something. You do as the below:
I will create video for you:

Submenu: have two child: Hide1 and Hide2
Hide1: have child name (4abc)
Hide 2: have child name( 1abc)
1abc: have child name (child1 of 1abc)
4abc: have child name (Child1 of abc)

Now You config for them the below:

Submenu
show Title: Yes
columns: 1
Submenu Column Width: colw1=802
parent item: menu item root

Hide1
parent item:submenu
show title: No
group: yes
Additional class: group-divison

Hide2
parent item:submenu
show title: No
group: yes

1abc
parent item: Hide1
show title: yes
columns: 1
group: yes

4abc
parent item: Hide2
show title: yes
columns: 1
group: yes
............................................................
You understand anything I spoken? ok. I will creat for you a video.
Please view this video:

Best Regards,
Huyen Tran