How to concatenate answers from 2 questions to define choices?

[WhitneyWeber]

I'm trying to create a field (ELEMENT_SEARCH) to define a choice_filter, based on two fields: ELEMENT_TYPE (A, P, C) and SEARCH_TYPE (Scientific, Common). I create ELEMENT_SEARCH as a field type of CALCULATE with calculation of ${element_type}&" - "&{search_type}, which fails with the error below. I then tried CONCAT(${element_type}," - ",${search_type}), but that error indicated XPath evaluation: cannot handle function 'CONCAT', although CONCAT is listed in the types tab. For example, I'm trying to get "A - Scientific" or "A - Common", to allow the user to select indicate to search animals/plants/communities by Scientific/Common Name. Can anyone suggest the appropriate calculation to use to achieve a concatenation of 2 fields? Or perhaps I'm going about this wrong?

[WhitneyWeber · Accepted solution]

Never mind - I resolved my own problem by having two separate select_one lists - one for common name and one for scientific name - and then calculating the response by adding the two results (calculation = ${scientific}+{common}). Since the questions are only shown when relevant, only one response is ever given and hence I was able to get the desired result!