You can do this in the Enterprise MFT Edition by adding a new (fake) Windows account, giving admin privileges and then making it the log-in-as user for the Windows/AD group authenticator on the Admin site. Instructions are given below:
Open CompleteFTP Manager
Go to the User panel
Click Add user -> Windows user(s)
Add user
Windows user(s)
Select any Windows account. It doesn’t matter which user, as we’ll be changing the user-name.
Now change the Username property to something that's not the username of an existing Windows account, e.g. WindowsAdminTemplate
Username
WindowsAdminTemplate
Make sure Show system users/folder/sites is enabled
Show system users/folder/sites
Select the user you just created
Click on the ellipsis button for Sites & home folders
Sites & home folders
Disable the Default Site and enabled the Admin site
Default Site
Admin
Set the home folder for the Admin site to /Admin
/Admin
Set the Access control property to Non-Windows
Access control
Non-Windows
You may also like to select WebAdmin as the home web-app for the user
WebAdmin
Click on the Groups link below the user list.
Click Add selected users to group -> admins
Add selected users to group
admins
In the Authenticators panel, select Admin in the For site dropdown
Authenticators
For site
Enable the Windows/AD Group authenticator
Windows/AD Group
Click on the Log in as column in the Windows/AD Group and select WindowsAdminTemplate
Log in as
Click Configure...
Configure...
Click Add allowed AD or Windows group
Add allowed AD or Windows group
Enter the name of the AD group that the users who you want to give CompleteFTP Manager access to
Click OK
OK
Click Apply changes
Apply changes