A collection in Plone 4 supports the selection of multiple folders as source for the path criteria.
A collection in Plone 5.2 allows only on folder reference for the path criteria.
You can add multiple path criterias but all of them are combined using AND -> zero hits (since one object can only be in one error).
Bug or feature?
That's odd. Volto supports multiple locations in its listing block (which is based on p.a.querystring):
See this example:
https://volto.kitconcept.com/collection-with-multiple-locations
Could be that this is just a restriction on the mockup/patternslib widget.
Strange, it didn't work in an earlier test, but is working now 
Can you please post your query? Multiple path criterias are combined into one.
Mea culpa...problem solved (problem this time on the user level). Customer maintained its news as "richdocument" instead as "News Item"...
