Show pages from category children

Hii, i need to show the pages from childern of a category.

Let’s say poges have category 2,3,4,5 and the parent of these categoryes is 1. I want to show all pages from these categoryes, in the category arhive.

PS. is about pages, with plugin ninja pages, that alow me set to pages categoryes and tags.

PPS Until recently everything works perfectly with default code, but I instal WPML plugin and mess a little thing here.