What crimes are senators and representatives immune of?

Art. 1 Sect. 6 Cl. 1 of the Constitution states that

[Part 1] The Senators and Representatives shall receive a compensation for their services to be ascertained by law, and paid out of the treasury of the United States.

[Part 2] They shall in all cases, except

• treason,
• felony
• and breach of the peace,

[Part 3] be privileged from arrest during

• their attendance at the session of their respective Houses,
• and in going to and returning from the same;
• and for any speech or debate in either House,
• they shall not be questioned in any other place.

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I am having a little bit of trouble understanding exactly what parts 2 and 3 are saying.

From what I understand, Part 2 is saying that a member of Congress cannot be arrested, unless they commit “treason”, a “felony”, or a “breach of the peace.” Part 3, though, is really the part that I find confusing.

Is Part 3 essentially saying that a Senator or Representative may not be arrested except for treason, felony, or breach of the peace anywhere, or is it for a specific place?

Also, are there any real examples of a Senator or Representative committing a crime other than those outlined above?