When I add an Execute Macro action, I pick the desired macro from a hierarchical list. After the selection, the Execute Macro shows just the name of the target macro.
As far as I can tell, the only way to locate the definition of the target macro is to select the All Macros group and look for a matching name. This fails when there are two or more macros with the same name in different groups.
I’ve found a work-around to the duplicate name problem: rename one or both of the duplicate macro names (e.g., add the Group name as a prefix or suffix).