Can I Place a Listing in Multiple Categories?
In WordPress, you can place one post or article under multiple categories. Similarly, GeoDirectory lets you place one listing under multiple categories.
Adding Multiple Categories to a Listing
When creating a new listing form, be sure that the Category field is a Multiselect. In such a case, you will be able to place all listings added via that form under multiple categories.
Alternatively, you can also change that field to Select -- in this case, the listings of that particular CPT can be placed under one category only.