Agile Hive introduces the new issue types "Solution Train Epic", "ART Epic" and "Team Epic". These allow hierarchical links between issues of the same project. This is not yet possible in Agile Hive Cloud. 

Do not mistake these for the standard Jira Epic issue type.

Identify the Epics in each project with a simple JQL search. This works for each level and project:

• issuetype = "Team Epic" and project = PROJECTKEY 
• issuetype = "Team Epic" and project in (PROJECTKEY1, PROJECTKEY1, ...)

The second option can be used for Teams in the same ART, as their Epics will all be migrated to Features in this ART project.

For ART level projects, use the following queries:

• issuetype = "ART Epic" and project = PROJECTKEY 
• issuetype = "ART Epic" and project in (PROJECTKEY1, PROJECTKEY1, ...)

The second option can be used for ARTs in the same Solution Train or the same Portfolio, as their Epics will all be migrated to Capabilities or Portfolio Epics respectively

For Solution Train level projects, use the following queries:

• issuetype = "Solution Train Epic" and project = PROJECTKEY 
• issuetype = "Solution Train Epic" and project in (PROJECTKEY1, PROJECTKEY1, ...)

The second option can be used for Solution Trains in the same Portfolio, as their Epics will all be migrated to Portfolio Epics in that project.

After having identified the Epics, you can use the bulk change function from the top right "Tools" menu.

After selecting all issues that you want to change, select the "Move" operation.

Select the project of the higher level where the Epics should be moved into. For Team level projects, that should be the ART project, ART Epics, the Solution Train project etc.

Review the changes and Confirm

After the move operation, the Epics should be in the selected target project. All child issues are still linked to it, but now, the issues do not lie in the same project anymore, thus making it an allowed configuration for Agile Hive Cloud to migrate.