Using a multi select field in results layout
One answer
When creating a query my multi select fields do not appear in the list selectable attributes.
Does RTC support the use of multi select fields in query results
As far as I know the attribute for a multi select field (typically a string) shows up in queries. At least i have seen it a couple of time. The issue is, that multi select fields are only done on presentation level. The mechanism stores a comma separated list of literal ID's in the field and the presentation translates that into the multi select presentation. This impacts the useability. The only mitigation I know is to change the literal ID's in the process configuration source. I haven't tried to change the ID's after I already had data.