Character Sheet, hit the "plus" tab, then open the Spellcasting section for a list of all your spell dc bonuses, which I believe are the totals for bonus DC from equipment, enhancements, destinies, feats, past lives... but do not include the contribution your ability stats make.
So if your bonus is listed as 50, your ability modifier is 40, your displayed DC (what appears on the command bar icon) for a 9th level spell should be 90 + 10 (base) + 9 (spell level) or 109. Keep in mind your effective DC will also be inclusive of any debuffs on the enemy like a curse.