you can use has_term to check if a post as a term which that is what “business directory categories” are (custom taxonomy terms).
something like:
if (has_term( $term, $taxonomy, $post_id )){
//do your thing
}
if you want to check if you are in a specific term ( like is_category
) you can use is_tax
if (is_tax( $taxonomy, $term )){
//do stuff
}
if you want to check if your object (post) is in a specific term ( like in_category
) you can use is_object_in_term()
if (is_object_in_term( $object_id, $taxonomy, $terms) ){
//do stuff
}