Sky Rift is a move introduced in Pokémon Mystery Dungeon: Super Mystery Dungeon and later games.
In Explorers of Time/Darkness/Sky, the closest equivalent to Sky Rift is Fly, which is learned by certain Pokémon like Pidgeot, Staraptor, and Skarmory. It allows them to fly to different locations on the map.
If you're looking for a move similar to Sky Rift in Explorers of Time/Darkness/Sky, Fly is your best option.