In a saucepan, mix water, dates, figs, sugar, lemon juice and orange juice. Let rest for 30 minutes then bring to boil. Reduce to medium heat and let simmer, stirring frequently, for 10 minutes or until mixture has thicken. Let cool.
In a large bowl, mix oats, flour, brown sugar, orange peel and salt. Add butter and with a pastry knife or with 2 knives, work the mixture until you have rough crumbs. Press uniformly half of this mixture in a 8 inches square pan (with parchment paper). Spread the cold dates garnish on the oat mixture. Mix the remaining oat mixture with hazelnuts. Distribute this mixture on the date garnish and press slightly.
Cook in a preheated oven of 350 F for about 45 minutes or until the top is lighly golden. Put the pan on a rack and let cool. Cut in squares. (You can prepare these squares in advance, let cool and cover with plastic wrap. They will be good up to 3 days in the fridge or up to 2 weeks in the freezer, wrapped with foil paper).