You can do this by following these steps;
1. Create your GitHub releases
For each repository you want to group into the release you need to put the same grouped directive name at the top of the GitHub release.
ReleasePage directives are written within an HTML comment block to stop GitHub from showing it as part of the release, but we will still be able to retrieve and display it on your Release Page.
The first repository release is for version 0.3.1-beta but is going to show as part of the overall software suite v0.3.0-beta release.
The second repository release is for version 0.2.5-beta but is also going to show as part of the overall software suite v0.3.0-beta release.
It's important to use the same value for grouped as this is how we know which releases to group together. You can also provide title or summary directives as shown (read more about them here).
2. Create a Release Page with both these repositories
Optionally give each repository a display name.
3. Enable group releases in the layout settings
4. Publish your Release Page and you're all done!
The release v0.3.0-beta now combines both the Management Portal and the Release Pages release notes within separate tabs.