Rambam in Hilchos Deos 6 (6&7) says:
6] When one person wrongs another, the latter should not remain silent
and despise him as [II Samuel 13:22] states concerning the wicked:
"And Avshalom did not speak to Amnon neither good, nor bad for
Avshalom hated Amnon." Rather, he is commanded to make the matter
known and ask him: "Why did you do this to me?", "Why did you wrong me
regarding that matter?" as [Leviticus 19:17] states: "You shall surely
admonish your colleague." If, afterwards, [the person who committed
the wrong] asks [his colleague] to forgive him, he must do so. A
person should not be cruel when forgiving [as implied by Genesis
20:17]: "And Abraham prayed to God..."
7] It is a mitzvah for a person who sees that his fellow Jew has
sinned or is following an improper path [to attempt] to correct his
behavior and to inform him that he is causing himself a loss by his
evil deeds as [Leviticus 19:17] states: "You shall surely admonish
your colleague." A person who rebukes a colleague - whether because of
a [wrong committed] against him or because of a matter between his
colleague and God - should rebuke him privately. He should speak to
him patiently and gently, informing him that he is only making these
statements for his colleague's own welfare, to allow him to merit the
life of the world to come. If he accepts [the rebuke], it is good; if
not, he should rebuke him a second and third time. Indeed, one is
obligated to rebuke a colleague who does wrong until the latter
strikes him and tells him: "I will not listen." Whoever has the
possibility of rebuking [sinners] and fails to do so is considered
responsible for that sin, for he had the opportunity to rebuke the
[sinners].
The commandment seems to be speaking about a case where the hate came about either because the hater has been wronged or because the other person has sinned or is following an improper path. Then it is right to rebuke the other person and not to keep the hate in his heart.
You ask “what extent is this talking about.” The Rambam does not seem to define this. If the wrong is sufficient to have generated hate, it seems that the mitzva to rebuke will apply.
