As David pointed out, this discourse is addressed to the disciples (actually it began with chapter 14 and goes through chapter 17).
John 15 is a beautiful poem in which grace or the kingdom of heaven if you please is a vine , and to be in the kingdom is to adhere to it. Actually it is a close analogue to Luke 20:9ff, Mark 12:1ff and Matt 20ff and actually has sources in Isaiah 5 and Jeremiah 12. The vineyard is thus a ubiquitous figure for the kingdom. John uniquely makes Jesus the vine. As I understand John, he has identified and equated Jesus (what Marcus Borg called the post-resurrection Christ) with the kingdom of God and set forth here the entrance requirements.
Remember, this is poetic, hence susceptible to multiple interpretations as all poetry is.
I don’t think that Jesus is telling the disciples to love only their own little group, although unfortunately that seemed to become the lodestone in the church rather early in its history– a tribalism and exclusivism that is the direct opposite of Jesus’ intention for us imho.
This has been the misunderstanding that has cursed the Christian Church even to the present, so that (some) Southern Baptists really believe that we are all going to hell. Soon after Constantine took charge of the Church, the ‘disciples’ started killing those who didn’t belong to their group. That misunderstanding (that we are to love only disciples) contradicts every thing that Jesus stood for imho.
John (particularly 1st John) and Jesus as well (according to the synoptics) believed that we relate to people in one of two ways: we love them or we hate them. They were teaching, it seems to me that we labor for the good of other people (love) or we don’t (hate).
Certainly John was saying special things to his disciples. We learn to love our group in one way and to love other people somewhat differently; but in both cases it’s love.
I loved my three boys, but each of them somewhat differently– according to their condition as I understood it. To love anyone (disciple or not) is to act in their interest as we see it.