Advanced Content Manager 2
For Magento 1
For Magento 2

Overriding/Changing Layout Update XML lists

To override/change markup using the Layout Update XML method, make a copy of:

/app/code/Blackbird/ContentManager/view/frontend/templates/content/widget/list.phtml

place in

/app/design/frontend/<Vendor>/<Theme>/Blackbird_ContentManager/templates/content/widget/list.phtml