What you did as Laguna way back in Disc 1 affects the areas accessible to you now. The following assumes you had Laguna trigger all the traps within the Centra excavation site:

Use the Meteor DP then head up the stairs. Inside the lobby, use the Curaga DP then enter the blue elevator in the center. Once on top, continue forward until you reach a T-intersection. Take the left route. Head forward until you reach a red elevator. Before using it, head down the stairs on the bottom right. Move south until you reach a ladder. Descend to a Confuse DP. Enter the small alcove on the right and search for a hidden Love Love G potion. After receiving it, head west.

Continue traveling west through the tunnel until you reach 3 metal doors. Look inside each of them to recieve gifts (they will be locked if you didn’t have Laguna tamper with the traps earlier). Starting from the right door: 1 Power Generator (lets Quistis learn Ray-Bomb), a Silence DP, and a Phoenix Pinion.

Head further west to find a copy of Combat King 005 on the ground. Continue to the back of the cave and examine a hidden area to the left for an Ultima DP. Backtrack to the red elevator and use it to return to the Lobby. Once there, head left and board the green elevator. Use the Holy DP then enter the small alcove on the left a little further up. Search inside to get a Spd-J Scroll then continue heading north.

Use the Save Point then head forward until you reach a fork in the road. Take the northern path. Once the party is kicked out, watch an FMV of the Pandora arriving at Tears’ Point.