Currently the Cross-Project-Release function does not allow for more than 1 release from 1 Jira project.

https://community.atlassian.com/t5/Advanced-Roadmaps-questions/Add-multiple-releases-of-a-same-project-into-a-cross-project/qaq-p/1259733

Scenario:

We have many components (essentially microservices) that are maintained in a single Jira project (essentially a team). Each of those components have their own versions and we track those using Jira Releases individually. For example, I have 

Component A

Component B

I may have the following Releases:
Component A-1.0
Component A-1.1
Component B-3.1
Component B-3.2
Component A-1.2

And I oftentimes want to group one or more of them into a single overall release which I want to use Jira Advanced Roadmaps to track. With the current limitation of only allowing a single release from a project, there is no way to display this in Advanced Roadmaps.