I am trying to trim some of our lower level category pages and we would like to have pages where all the links under subcategory pages will show under parent category page grouped by subcategories.

Now we have Category page and Subcategory pages like:

CATEGORY PAGE

SubCategory1 Name
SubCategory2 Name
SubcategoryN Name

SUBCATEGERY1 PAGE
Link1
Link2
Link3

SUBCATEGERY2 PAGE
Link5
Link6
Link10

SUBCATEGERY_N PAGE
LinkN
LinkM

but we would like to have only CATEGORY page like:

CATEGORY PAGE

SubCategory1 Name
Link1
Link2
Link3
SubCategory2 Name
Link5
Link6
Link10
.....
SubCategoryN Name
LinkN
LinkM

I tried to run links loop inside category loop but apparently it doesn't work like that.
Can anybody help to achieve our desired outcome?
Thanks!