What does it mean of 1 Corinthians 2:8

Your question is taking a single verse out of context and expecting it to be literally understood. That's a regrettably easy mistake to make by students of the Bible, both new and practiced. Let's look at what Paul was saying, and you'll immediately realize that I'm not even going back far enough to completely understand Paul's original point — I am only going back far enough to understand the verse in your question. 1 Corinthians 2:1-8:

(1–5) And I, brethren, when I came to you, came not with excellency of speech or of wisdom, declaring unto you the testimony of God. For I determined not to know any thing among you, save Jesus Christ, and him crucified. And I was with you in weakness, and in fear, and in much trembling. And my speech and my preaching was not with enticing words of man’s wisdom, but in demonstration of the Spirit and of power: that your faith should not stand in the wisdom of men, but in the power of God.

Paul starts this part of his letter off by referring to an issue he's addressing in a larger context, one that's found in chapter 1 but not here. I'm not going to go into that because it would only distract us from answering your question. What Paul is doing is setting up a "sub-lesson." He does this a lot in his writtings — taking advantage of his primary subject to teach one or more secondary subjects.

What is he setting up? The idea of believing what God teaches us versus what the World teaches us — "that your faith should not stand in the wisdom of men, but in the power of God." Remember, that's the secondary issue that he's talking about and it applies to verse 8.

(6–8) Howbeit we speak wisdom among them that are perfect: yet not the wisdom of this world, nor of the princes of this world, that come to nought: but we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory: which none of the princes of this world knew: for had they known it, they would not have crucified the Lord of glory.

"[Speaking] wisdom among them that are perfect" is talking about the people who become perfected in Christ. It's the wisdom of God that does this, not the wisdom of the world, nor the wisdom of the leaders of the world.

Paul talks about the wisdom of the world later in this chapter. He identifies it as the yearnings of the "natural man" (1 Corinthians 2:14), who sees the things of God as foolishness and can't understand them.

The wisdom of world leaders (the princes of the world) is, like that of the natural man, self-centered to perpetuate their power base. The leaders of the world have the capacity to make things right, but so often do not. Paul's readers may have recognized the phrase from the Gospel of John, chapter 14, verse 30:

Hereafter I will not talk much with you: for the prince of this world cometh, and hath nothing in me.

(See also Ephesians 2:2; John 12:31; and John 16:8-11)

This reference to Satan, who tempted Christ with (among other things) worldly power, is reflected in his complaint about the princes of the world, who also seek power. Their wisdom is not equal to God's, which John explains with what @brasshat correctly identifies as a bit of hyperbole. Had the princes of the world instead sought the wisdom of God, they (using what would have been the well-known story of how Jewish leaders and local Roman leaders conspired to kill Christ with hyperbole to label all worldly leaders) would never have killed the Messiah.

Therefore, Paul is not saying that every leader in the world contributed to the death of Jesus Christ in A.D. 33. I don't believe it was even possible at the time for all the leaders of the world to know of one another. As you read Paul's writings, you will realize that he often uses hyperbole and grandiose descriptions to keep his audience's attention. Here, Paul is merely using the reference to underscore his purpose for teaching this sub-lesson: the wisdom of God is better than the wisdom of the world and the wisdom of world leaders. And the death of Jesus Christ is proof of that fact.

To me, it seems the speaker is saying that all the rulers from every part of the world crucified Jesus somewhere on 33 AD.

"But we speak the wisdom of God in a mystery, the hidden wisdom which God ordained before the ages for our glory, which none of the rulers of this age knew; for had they known, they would not have crucified the Lord of glory." (1 Cor. 2:7-8)

The speaker is saying that none of the rulers of this age understood the wisdom of God.

Then he says, if they had known the wisdom of God (the fact that Jesus was indeed the Son of God), they would not have crucified Him.

The last "they" in verse 8 is probably referring to the rulers complicit in Jesus' crucifixion. 3 come to mind.

Herod the tetrarch of Galilee: "Then Herod, with his men of war, treated Him with contempt and mocked Him, arrayed Him in a gorgeous robe, and sent Him back to Pilate." (Luke 23:11)

Pontius Pilate the governor of Judea: "But they were insistent, demanding with loud voices that He be crucified. And the voices of these men and of the chief priests prevailed. So Pilate gave sentence that it should be as they requested. And he released to them the one they requested, who for rebellion and murder had been thrown into prison; but he delivered Jesus to their will." (Luke 23:23-25)

Caiaphas the high priest and president of the Sanhedrin: "And one of them, Caiaphas, being high priest that year, said to them, “You know nothing at all, nor do you consider that it is expedient for us that one man should die for the people, and not that the whole nation should perish.” Now this he did not say on his own authority; but being high priest that year he prophesied that Jesus would die ... Then, from that day on, they plotted to put Him to death. (John 11:49-51, 53)

"the high priest answered and said to Him, “I put You under oath by the living God: Tell us if You are the Christ, the Son of God!” Jesus said to him, “It is as you said ... Then the high priest tore his clothes, saying, “He has spoken blasphemy! What further need do we have of witnesses? Look, now you have heard His blasphemy! What do you think?”. They answered and said, “He is deserving of death.” (Matt. 26:63-66)