List linked issues by Assignee

You would like to access the Blocked Test cases dimension to get this counter.

 NonZero(SUM(
    Filter(
      Descendants([Blocked Test Cases].Currentmember, [Blocked Test Cases].[Blocked Test Cases]),
      -- filter out Blocked Test Cases related to issues in report
      ([Measures].[Issues created],
      [Assignee].CurrentHierarchy.Defaultmember, 
      [Time].CurrentHierarchy.Defaultmember) > 0),
    -- search for Blocked Test Cases in Issue dimension, use in a tuple with measure, assignee and time, ignore anything else with DefaultContext    
CASE WHEN     
DefaultContext((
      [Measures].[Issues created],
      [Issue].[Issue].GetMemberByKey([Bugs].Currentmember.Key),
      [Assignee].CurrentMember, -- filter linked issues by assignee
      [Time].CurrentHierarchyMember, -- filter linked issues by time
      [Blocked Test Cases].DefaultMember
    )) > 0
THEN 1 END
 ))

The formula might work slow in accounts with a lot of issues. You can consider an alternative by importing a new field with calculated javascript code counting issues with a particular link:
In this community post there is an example at the end of the thread:

Daina / support@eazyi.com