Paul went up to the third tier of Heaven which was not located on the earth: does this show that the saved go to heaven when they die?

No. Whatever happened to Paul when he was ‘caught up to the third heaven’ (2 Cor. 12:2) happened to him when he was alive, not dead, so it is no indication of what happens to people when they die.

For more on the third heaven, see the answers to: ‘What is the third heaven? (2 Corinthians 12:2)‘ which includes some material related to problems Paul was dealing with in Corinth related to Jewish myths.

For more on what happens when people die, see the answer to ‘Where do we go when we die?‘.