I need to make a small change to the AdminGroup.aspx file, but don't want to make it in the C:\Program Files\EPiServer\CMS\5.2.375.7\Application\UI\Admin\AdminGroup.aspx as it is shared by other EPiServer sites.
EPi4 used shadow folders to accomplish that.
You can use VirtualPathMappings to handle that. The web.config would be settings will be similar to this:
Thanks for your help