Show some Events (also) as News

I have a running site where I want to show some Events (also) as News.

Since the AND option in Collection is gone: Is there another 'easy way of doing this'? Any suggestions on how ? Maybe it is possible to use a content rule to always add a keyword ('Newsitem') to all NewsItems and then manually add it to whatever Events.

PS: I can not place all News or Events in same folder, since authors have access to only sub-sections.

"one or more" should available as collection criteria.

Sorry, did not understand that.

Basically, I want 'News' to show

a) News Items
b) Events that are marked as 'News Items'.

Since this is just temporarily (Because of Covid 19, the events are not happening at the moment) it would be nice if I did not have to 'program anything'.

What mean

Via a Behavior? Or is a Event a Contenttype News Item with enabled Eventbehavior?
I thought you would like merge News Items and Events in a Collection View.

I want to show

a) Type Matches 'News Item'
b) Type Matches 'Event' AND Subject contains 'newsitem'.

You can only use the Subject in both, thats all, or? The Collection show results of the Subject filter 'newsitem'

with the 'new' collection I can only show (I think)

a) News Items AND Events


b) (News & Event) Items with subject 'newitem'.

So adding a subject feels like the best way (=less work). I can not trust the users to remember to add 'News Item subject', but I can let them add it to the Event (since only a few users do this)

Or you use Mosaic and place two listings on the page: one for News Item instances and one for Event instances with subject 'news'. Would imagine placing the two listings side by side.