Alfonso,
Unfortunately, there seems to be no appropriate method in eazyBI to implement such use case. Javascript calculated custom fields can create a new dimension (like the example you have found) but we cannot add more data (e.g. Issue link type) into the dimension during the Javascript execution.
The closest workaround for this case would be to create separate dimensions from each link type and to have a report like this:
Please, check more on how to configure the import of specific issue links:
https://docs.eazybi.com/eazybijira/data-import/advanced-data-import-options/import-issue-links
Kindly,
Janis, eazyBI support