Does anyone know if it is possible to make a single sub-area in the
portal show up under more than one category on the topic map?

Basically, we have seven different branches of our taxonomy
immediately under the topic map, and then have sub-areas under those
topics. Some of our sub-areas relate to more than one of the main
seven branches, and I need to make a link to those areas show up on
more than one place of the topic map.