All workflow post functions in WMB Cloud has the option to be filtered by a JQL query. For example, let’s say you want to add a comment in a given transition, but just for the issues of type Bug.
In this case, you should add this filter to the Additional JQL field:
issuetype = "Bug"
Please notice how it is not necessary to reference the current issue. WMB Cloud will do this for you.
The resulting configuration will look like this: