Insight Referenced Custom Field

[Anna Protopapa]

Is there a way to change an Insight Referenced Custom Field from single to multiple?

[Björn Gullander]

Hi, 

No to make it possible to change from multiple to single after creating the field, you must use the Insight Object/s field type. 

By setting the Filter Issue scope  to something like Key = ${customfield_12345} you can make that field work as a referenced field (in this case filtering by the value in field with id= 12345.