As of R2020b onwards, both "uibuttongroup" and "uipanel" components support the Enable property when they are parented to a "uifigure". Refer to the ButtonGroup documentation to learn more about this.
For releases before R2020b:
The container objects do not have a property that can disable all of its children. However, you can obtain the container's children, and then modify their Enable properties with a single command:
% Here 'c' is the handle to a container object
children = get(c,'Children');
set(children,'Enable','inactive');
