hey nelly,
I think you are looking in the wrong place ,
as you attached , last picture – you looked into Item Object and not into Category.
moreover you need to locate a list that Type Cascade and NOT Simple OR Dynamic.
see pic attach 

Nelly –

The problem here is that you are using a “read-through” field in your search Criteria.  

This is not always a problem and can be a very useful feature, however – it can also lead to undesirable results as there is no distinction between Parts and Documents when setting up these ITEM read-through fields on the Affected Items tab.
For example – Lets Say:
– Page_Two.List01 is ‘Item Category’ for the PARTS class
-Page_Two.List01 is ‘Document Type’ for the DOCUMENTS class

If the  read-through field  (Item P2 List01) is enabled on the Affected Items Tab  –
– the ‘Item Category’ value is displayed (from the Item record) if the affected item is a PART
– the ‘Document Type’ value is displayed (from the Item record) if the affected item is a DOCUMENT

It gets even more confusing if I’ve renamed the Read-through field “Item Category” since that isn’t what it is actually being displayed for a Document Affected Item.

Even if Page_Two.List01 is “Item Category” for both Parts and Documents – if they use different lists (which appears to be the case for you) the Advanced Search will not merge the values of the separate lists.

This is a design flaw, in my opinion.  I’ve never really heard this addressed nor am I aware of it being fixed in any recent updates (currently on 9.3.2).  I have done a lot of testing on read-through fields, however, and there is a lot that does and doesn’t work that isn’t mentioned anywhere in the manuals.

If you do use ITEM read-through fields on the affected items tab – I would highly recommend using an attribute that is either not used by both Parts and Documents or –  if it is used by both – make sure that the attribute is the same and uses the same list.

Please let me know if you have any further questions on this.