A foreign key element will be shown in the custom layout only if it has been rendered in the main tab - 6.2

Talend Data Fabric Release Notes

EnrichVersion
6.2
EnrichProdName
Talend Data Fabric
task
Installation and Upgrade
EnrichPlatform
Talend Activity Monitoring Console
Talend Administration Center
Talend Artifact Repository
Talend CommandLine
Talend DQ Portal
Talend ESB
Talend Identity Management
Talend Installer
Talend JobServer
Talend Log Server
Talend MDM Server
Talend MDM Web UI
Talend Project Audit
Talend Repository Manager
Talend Runtime
Talend SAP RFC Server
Talend Studio

To display a foreign key element in the custom layout, you need to render it in the main tab.