I can't seem to find Dervish Dance in the Pathfinder feats. It should be in ultimate combat which is included in the PF core supplements. I tried simply adding it via homebrew but can't figure it out.
Ultimate Combat has no "Dervish Dance" in the feat section of the book. Closest I can find is 'Dimensional Dervish'.
Inner Sea World Guide and Qadira Gateway to the East both have the feat 'Dervish Dance' though.
Ultimate Combat contains the Bard Archetype 'Dervish Dancer'
No reply from OP. Closing.