Hey JP,
I’m awfully sorry for replying only now, a notification about this thread must have slipped through my inbox.
The theme does not imply a possibility to have two taxonomies for the “project” post type out of the box, which means you will need to perform some customization to achieve this. Since this is not covered by the ThemeForest support offer, you will need to use a help of a professional developer (e.g. on Envato Market) in case you are not familiar with php yourself.
There are at least two ways to get a second taxonomy to work with the “project” post type:
1). The cleanest, but also the longest one: register a new taxonomy using the “register_taxonomy” function and then add an association with the “project” post type either by adding a “taxonomies” parameter in the “register_post_type” arguments on lines 471-483 of the theme’s “functions.php” file, or by using a separate “register_taxonomy_for_object_type” function.
2). Extend the default “tag” taxonomy so that it can also be used with projects in addition to posts, either by adding a “taxonomies” parameter in the “register_post_type” arguments on lines 471-483 of the theme’s “functions.php” file, or by using a separate “register_taxonomy_for_object_type” function.
Sincerely,
Andrii / Satori Studio