to create own conditional tags for business directory in wp

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
}