Could you please detail ?

Is it on the "add link" functionality that you expect search function ?
Then you have it : the "magnifying glass" icon lead you to select screen where filters on id, type and name are active.

So, how I can create filter based on items in linked list?

use the "magnifying glass" icon

No, it is not working

what is not working ?

use the "magnifying glass" icon to search on the linked items

Coul you please detail ? I don't understand.

When you click on the "magnifying glass" icon beside the link item list, you get a list of items to be linked. There you can filter on id, name and type.
Isn't it what you get ?

I am talking about items linked (linked elements) to a Ticket, for example. If I use the "magnifying glass" and put name of linked item from the list of linked elements it is not filtering items using this criteria

I understand now.
We were not dealing with same thing.

I was talking about possibility to search for an item when adding a link. So I talked about the "magnifying glass" in the "add link" pop-up.

What you expect is that filtering on an item could also filter on the linked elements.
If I understand correctly, what you expect is that being on an activity, searching for text "xxx" will return items with "xxx", including activities linked to tickets with "xxx".
Is that correct ?
If so, then answer is no : this does not work and will probably will never. Linked elements are only stored as id, and it would be a mess (in programming and performance impact) to look for any item, seach for the text and then return elements linked to these items.

What could be done is to seach for notes, and return elements including the searched text in notes (this in not working today).

Thank you very much! When you plan to have notes search workable?

Possibly in V2.4 😉

Will be great!