The developers of the application offer users the possibility of accessing various information (tutorials, manuals, guidelines) using their website. There is a section on their website called Support which offers these resources.
There is also a page with instructions on how to operate with groups. I recommend you access it to read all about it.
Support page: http://help.asctimetables.com/#392
Note: There are many other topics on the page, so make sure you'll check those as well. Scroll up to see the list with the topics.
