Tibor Nebula

The Tibor Nebula was an interstellar cloud located within Federation space in the Alpha Quadrant.

In 2374, Starfleet planned for the Seventh Fleet to cut off a supply line the Dominion was trying to establish through Betazoid space into the Argolis Cluster (with the presumed purpose of the Jem'Hadar attacking Vulcan) with a battle near the nebula. (DS9: "The Reckoning")

This nebula was only mentioned in dialogue.
This nebula's quadrant of origin is inferred based on the positions of the star systems Beta Zeta (Betazoid space) and Tagra (Argolis Cluster) in the Alpha Quadrant, as seen in the star chart appearing in the Star Trek: Picard episode "Maps and Legends".