The source of the focus is you, because you are the one focusing. The object of one focusing on the Holy Spirit is of course Jesus, or the Father, because they're all the same person.
One God, three Persons. Each person of the Holy Trinity is God.
We created beings are used to having one substance and one person. It is not so with God.
This seems a mystery, but when we say "God is Love" we are asserting that God is more than one person. For love is between persons.
But why three persons? This is because God the Father and God the Son love one another: and the Love between them is itself fully God: the Third Person of the Trinity whom we call the Holy Spirit.
This incidentally is why the Creed says that the Holy Spirit "proceeds from the Father and from the Son"