is it correct that the filter function isn't available for the 30-day trial version but only for the 'full licensed' version?
I'm using Arcgis Online.
I've moved your post into the Arcgis online space. You will get a much better answer here as the GeoNet Help is intended for community help and feedback. I have also added in a few additional tags. You can see more on the community structure, and what topics are under each space from the following documents:
ArcGIS Discussion Forums Migration Strategy
Thanks!
Don
During the 30 day trial the filter function is available as it would be in the full licensed version
Note the considerations for filters at the bottom of this link.
http://doc.arcgis.com/en/arcgis-online/use-maps/apply-filters.htm