After completing the construction of the Beis Hamikdash, Shlomo gathered the Elders, the heads of the tribes and the leaders of the ancestral families to bring the Ark of the Covenant from the City of David. Verse four relates, “They brought up the Ark of Hashem and the Tent of Meeting and all the sacred vessels that were in the tent …”
Rashi addresses what is meant by the “Tent of Meeting” - that Moshe made – Shlomo hid when he built the Beis Hamikdash as it is taught in the Tosefta of Sotah.”
The Tosefta there (13a) says, “When the first Beis Hamikdash was built, the Tent of Meeting was hidden. Hidden with it (the skin coverings – “Tent”) were the hooks, planks, bars, boards and sockets.”
The Metzudas Dovid adds, “The Tent of Meeting was in Givon and from there they brought it up to hide in the storage area in the House of Hashem – in the “aliyos” - the second story compartments above the Sanctuary and the Holy of Holies.”
The Mishptzos Zahav infers from the plural usage of the “aliyos” that parts of the Mishkan were stored in different areas. It would seem that the planks and sockets of the Sanctuary were hidden above the Sanctuary and the planks and sockets of the Holy of Holies were hidden above the Holy of Holies.
It should be noted that while the Abarbenel and the Malbim seem to agree with Rashi and the Metzudas Dovid, a gemora in tractate Sotah (9a) says that the Tent of Meeting and its parts were buried in the tunnels under the Sanctuary.