From StrategyWiki, the free strategy guide and walkthrough wiki

• - Moves your cursor around in battle and scrolls though the menus(in and out of battle)
• - Confims actions, brings up map menu during battle,when on unoccupied square, and scroll through dialogue during a cinima scene.
• - Cancels the current action, returns you to the previous part of the menu, and if tapped or held during text it rapidly scrolls through it.
• - Scroll between your units that you have not yet commanded during battle.
• - Brings up data for the unit you have the cursor over or gives more specific data for certain items (during battle).