Three days after completing the Planar Prison quest for Haer'Dalis, Talk to Pai'Na in her lair in the Lower Tombs beneath the Graveyard District. Leave the docks district in chapter 2 or 3 with Minsc in the party, at least 2 days after first entering it with Minsc. Myara approaches when you first exit the circus tent. Unfinished Business (“UB”) is designed to restore many of the cut items, quests, and encounters from the game’s final release, as well as try to tie up some of the “loose ends.” For Baldur's Gate II: Enhanced Edition some components have meanwhile been included in the game itself and are deprecated in the mod.
As of Version 28, most all UB components are BG2:EE compatible.