I tried myself at it but it’s exactly like Fei-Ling said, projects aren’t a ref to news, so you hit an impossibility.
It’s delicate to use multi refs with filters, it’s quite limited. For instance we can’t use it to mimick a real tag system (vocabulary, taxonomy, whatever you call it). The conclusion is we really need a tag system in Webflow CMS For now users try to approach it using multi-refs, options fields, but it’s limited.
So the solution here must be a design solution: change either the design (content) or the database structure. One way to approach it is to count less on automation and more on editorial. What I mean by this is that there is always a finite amount of CMS items, and thing you’d want to be automatic (such as the related news section) could be dome manuall, like deciding for each item what news post you’d want to display. I understand that it won’t be automatic anymore and that you may have to edit items to link more recent news, but having to manually chose what linked content you propose inside of an item can lead to a better editorial quality.