Is it possible to values in single list based on values selected from other single list?

[Raj Kumar]

Example   - Like we have A and B two single list field. We want to populate values in list B based on values selected in list A. 

Is it possible using using Script runner?  

[Nic Brough -Adaptavist-]

First, have a look at the built-in "cascading select" field, as that's what your question seems to be describing.  If that can meet requirements, use it.

If that doesn't do what you need, then yes, Script Runner Behaviours can link fields in all sorts of ways.  Start at https://scriptrunner.adaptavist.com/4.3.1/jira/behaviours-overview.html