Hi,
The simplest solution for this use case could be to count the number of assignees where there are any issues created for this assignee in the period.
The formula would be the following:
NonZero(Count(
Filter(Descendants([Assignee].CurrentMember,[Assignee].[User]),
[Measures].[Issues created]>0
)
))
Kindly,
Janis, eazyBI support