Path: $GLOBALS[‘TCA’][$table][‘columns’][$field][‘config’] Type: string Scope: Display / Proc.
This works like foreign_sortby, but in case of using bidirectional symmetric relations. Each side of a symmetric relation could have its own sorting, so
symmetric_sortbydefines a field on the foreign_table where the sorting of the “other” side is stored. This property requires that the foreign_field approach is used.