“The Spirit.” This is Yahweh, who appeared to Ezekiel in Ezekiel 8:2 and 11:1, and now takes Ezekiel back to Chaldea and the exiles there, and at that point the vision Ezekiel was having stopped (see commentary on Ezek. 8:2).
“by the spirit of God.” This is most likely the spirit that God puts on prophets to best communicate with them, often called “holy spirit” (cp. Num. 11:17, 25). It could, however, also just be a reference to God like in Gen. 1:3. [For more on the spirit of God, see Appendix 11, “What is the ‘Holy Spirit’”].
“the vision that I had seen went up from me.” This was the end of Ezekiel’s second vision, which began in Ezekiel 8:1 (see commentary on Ezekiel 8:1).