The calculated member looks for the selected member of “User_defined_dimension” and retrieves its name - if it matches, then returns the Issue resolved value accordingly.
In your report, the “User_defined_dimension” is not used at all, therefore, the measure always returns the default member of this dimensions (with the name “All User_defined_dimensions”) which does not match the conditions. In the result, you always get an empty value
You may do the following changes:
In “User_defined_dimension” create a calculated member that aggregates all members with names matching AA and BB, similarly to this member (I named the calculated member “AA and BB”)
[User_Define_Dimension].CurrentMember.Name MATCHES "AA|BB"
Then, in measures, create a new measure, that retrieves resolved issues from issues with AA or BB values in User_Define custom field. Use a tuple construction for calculation: read more here https://docs.eazybi.com/display/EAZYBI/Calculated+members#Calculatedmembers-Tuples
The formula would be like the following:
[User_Define_Dimension].[AA and BB])
Use the measure instead of yours.