I’m also using regex to differentiate hostnames (WHEN (REGEXP_MATCH(Page URL, ‘.www\.hostnameA.’)) THEN ‘Hostname A’). When I add this regex as a filter to a standard dashboard, f.e. comparing Channels & Visitors for one hostname in particular, I get somewhat weird results like the screenshot below.
Does regex works differently in looker studio than in the Piwik interface? Or will this issue have something to do with the matter Filters do not work with Data Studio Connector (from 28.11.) - #3 by dave