The business objects created by Visual Builder expose a powerful REST service interface that includes the ability to use complex query conditions to filter the list of records they return. This is done using the q parameter as described here. In the current version of Visual Builder we didn't expose a design time access to the q parameter and rather provided an abstraction through the filterCriteria approach for defining queries. This saves you from the need to learn SQL syntax for queries - and generates the q parameter for you.
But you can actually use the q parameter directly as well - passing it as one of the uri parameters when you call the GET REST method. This can be useful for example when you want a more complex query condition. For example if you want to use the SQL in clause - something like "Where name in ('joe', 'dave', 'jane')".
For regular information become a member in the Developer Partner Community please register here.