Don’t wanna disappoint you, but this time I have no choice. Having spent some time within Dabble DB in order to clear up things with dependent dropdown function I’ve got deplorable results.
There is no such option at the present time, what is confirmed also on forum.
What I would like to mention, it’s only my personal impression, of course, but I think that Dabble DB is much more developed for data analysis, rather than for data input. I state this after reviewing different options of Dabble DB functionality. If you don’t take my words for this, you can simply check out actual Dabble DB testing showcases.
But if you need just to analyse the data there is another system I would recommend you to take a look at Good Data. I guess in future Good Data may be a worthy competitor of Dabble DB.