Using Cascade Select on Select Multiple - Need to filter choice list using the same choice list

[mrosekulick]

Hello! I am working on a Survey123 form for a Bat Survey. 

I have two fields with the same multiple select choice list: Known Species and Potential Species.

I'd like to filter the Potential Species field to not show any choices that are selected in the Known Species field.  

I'm struggling with how to do this - thanks for any help!

[ZacharySutherby]

Hello @mrosekulick, 

We have a sample available in Survey123 Connect that demonstrates cascading selects and there are a few samples in there that demonstrate configuring a choice list with select_multiple questions. You can use the selected() function or a regex() expression to do the filtering. 

Please also check out Ismael's Choice filters Esri Community blog: https://community.esri.com/t5/arcgis-survey123-blog/survey123-tricks-of-the-trade-choice-filters/ba-...

The important note from that is "If the expression evaluates to true, then the choice is kept. If the expression evaluates to false, the choice is dropped."

[mrosekulick]

Thanks, Zach! I found the sample, which is super helpful! It doesn't quite cover the scenario I have.... Basically I want to find a way to say "If KnownSpecies contains xyz choices, then don't display xyz choices in PotentialSpecies". I think I'm struggling because they are both select_multiple fields and I'm not sure how to phrase the syntax. I'm also a little rusty in Survey123. 🙂

Thanks again!

[ZacharySutherby · Accepted solution]

Hello @mrosekulick, 

The select_multiple samples available in the connect sample demonstrate displaying choices, but including a not() function around the function removes choices from the list. I've attached a sample that demonstrates taking choices out of a select_multiple list. 

[mrosekulick]

That did the trick! Thank you so much!!