You can easily add those items to the Join form, but always consider keeping the form as short as possible. Prospective members aren't keen on supplying too much information until they actually become a member.
This is a question you could include in the general profile and you can even make it mandatory. In fact I have it included in my site's profile and I use a commercial routine designed by AntonLV to make the answers searchable. For example, if a member includes Friendship in the field, he can click that word and it will show every other member interested in Friendship.
As I read your question, I get the impression you may not know your way around the Profile Fields Builder in Admin. This is actually where it all starts, but before I ask more about that, can you please tell me why you're using Dolphin 7.3.5? If you're building a new site, or one that doesn't have members, you would be far better off using Dolphin 7.4.2. They react the same, but 7.4.2 is designed for PHP 7.2 which should allow you to operate for many years into the future.
Another thing that confuses me is your question today. Do you want the information the person enters in the field to decide what Profiles he or she can view? As I said earlier, Anton's brilliant module allows members to filter profiles based on what they're here for, but generally, every member can see every profile. That's what Social networking is about. If you wish to filter profiles from the outset, that's something I can't help you with.
Screenshot 1 shows the fields the prospective member would be asked to enter. It's a multiple choice question.
Screenshot 2 shows how the results appear in the profile. With Anton's mod "Searchable Fields" any of those items can be clicked to reveal every member with similar tastes.