Second parameter holds relation name. But be warned - there is difference between relation name expected in this parameter and each direction descriptions of relation.
Every relation in JIRA has the name and descriptions of its 2 directions. If you want to have selected only one specific direction of given relation you can use the third parameter of the function which can have 2 values inward/outward. Search Linked Issues for JIRA don't use direction descriptions, only relation name.
Please as your administrator to get real relation name. Relation names could be found in JIRA administration - see jira documentation.
Sample relation configuration can be:
- relation X name - 'Cloners'
- inward direction description of relation X * - 'Clones'
- outward direction description of relation X * - 'Is cloned by'
So you could query like this:
- issue in linkedIssuesFromFilter("filter name", "Cloners", "inward")
- issue in linkedIssuesFromFilter("filter name", "Cloners", "outward")