User trash can is specific to each user, so even if a user is manager in site or part of SITE_ADMINISTRATORS group, he/she can see files/folders deleted by himself/herself only (i.e. where he/she is owner of file/folder), Unless user is Administrator (part of ALFRESCO_ADMINISTRATORS group which basically gives FULL_CONTROL permission on repo).
An admin can see files/folders deleted by every user is trash can.
Permissions are checked at the core and api level: https://github.com/Alfresco/alfresco-remote-api/blob/master/src/main/resources/alfresco/templates/we...
If user has has FULL_CONTROL permission on node or user has originally deleted the files/foldders then files/folders appear/added to trash can view.
public boolean hasFullAccess(NodeRef nodeRef)
String currentUser = getCurrentUser();
String archivedBy = (String) nodeService.getProperty(nodeRef, ContentModel.PROP_ARCHIVED_BY);
if(!userNamesAreCaseSensitive && archivedBy != null)
archivedBy = archivedBy.toLowerCase();
The simplest way for you would be, to make the authorised user as admin whome you want to allow to see files/folders deleted by all users if that matches your use case.
create custom endpoint and extend usertrash can functionality to call your custom endpoint and return archive nodes to authorised users, you can find an example of extending trashcan here: https://javaworld-abhinav.blogspot.com/2020/01/display-more-than-50-items-per-page-in.html
Or extend the apis (given above) [NOT RECOMMENDED]
(ACSCE, AWS SAA, Azure Admin)