On the third day, he will raise US up

[tonychanyt]

Hosea Prophecied more than a century before the Babylonian exile, Hosea 6:

1 Come, let us return to the LORD; for he has torn us, that he may heal us; he has struck us down, and he will bind us up. 2 After two days he will revive us; on the third day he will raise us up, that we may live before him.

In the historical context, it was about the destruction of the Israel kingdoms and its restoration.

Does the "us" refer to the Israelites or Jesus? Does it apply to Jesus' resurrection?

Yes, on the road to Emmaus, Jesus told the two disciples whom he met,

25 “O foolish ones, and slow of heart to believe all that the prophets have spoken! 26 Was it not necessary that the Christ should suffer these things and enter into his glory?” 27 And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself.

Jesus encouraged them to read Jesus into the Scriptures.

Paul alluded to it in 1 Corinthians 15:

4 that he was buried, that he was raised on the third day according to the Scriptures,

Jesus and Paul's passages do not specifically mention Hosea, which is why scholars disagree. Hosea targeted Israel for this prophecy, but it was a double prophecy ultimately fulfilled in Christ.

Luke 9:

22 And he said, "The Son of Man must suffer many things and be rejected by the elders, the chief priests and the teachers of the law, and he must be killed and on the third day be raised to life."

Isaiah 49:

3 He said to me, "You are my servant, Israel, in whom I will display my splendor."

Jesus fulfilled the above by being the true vine, the true Israel.

Hosea's prophecy applies to the historical Israelites and the true Israel in Christ.