[TYPO3-ttnews] Filtering a listed view using category

[David ARNOULT - Edition & Internet Operations]

Hi,
 
Is it possible to filter a list view that is already using a category filter ?
 
Imagine you have this category structure:
.         Cat1
.         Cat2
.         Cat3
o    SubCat3-1
o    SubCat3-2
 
Some articles are Cat1 or Cat2, but some are sharing Cat3 like SubCat3-1 or SubCat3-2. They are all in same folder.
I wish to display a list showing Cat2 only (OK) AND SubCat3-1 or SubCat3-3 with a CATMENU on the same page.
.. When I do that Cat2 filter is not active anymore...
 
Any idea will be appreciated...
 
Thanks
 
David