Display members first name only with code

So, I'm using a plugin that calls this <p><a href="'.bp_get_member_permalink().'">'.bp_get_member_name().'</a></p> to display a link under a friends avatar and I was wondering how I could add some code this part '.bp_get_member_name().' so that it displays the members first name only. I also have the plugin "BuddyPress Real Names" install so I can generate custom field id's. The users first name field is 17.
Thanks