Assuming Orah and the other Cleric are normally Clerics and are not tokens, you own and control both, and the latter's converted mana cost is greater than 3, this will work in two cases:
If you sacrifice Orah and the other Cleric at once while paying for the same spell or ability (e.g., Dark Supplicant's ability), this will work.
This will likewise work if you sacrifice both creatures at once while the same spell or ability is resolving (e.g., Balance).
In both cases, Orah's triggered ability will trigger at least twice (once for itself and the other Cleric) and the creatures will go to the graveyard before the abilities go on the stack, so that the ability referring to the other Cleric can target Orah this way in time (C.R. 601.2i, 117.3b, 117.5, 603.3d, 601.2c, 603.10a, 603.10, 603.6c, 700.4). See also this thread.
However, this will generally not work for spells and abilities with a cost of sacrificing one creature at a time (such as the abilities of Nantuko Husk, Ashnod's Altar, and Altar of Dementia). This is because in general, once you sacrifice Orah or a Cleric with such a spell or ability, Orah's triggered ability will trigger, but then you will have to put the ability on the stack (and you must target, if possible, a "Cleric card with lesser converted mana cost [in] your graveyard" than the creature just sacrificed, right then and there) before you get priority to cast any more spells or activate any more abilities (C.R. 601.2i, 117.5, 603.3d, 601.2c, 117.1a-b).
There's a third case, where that is possible, namely, when the presence of the 5-mana cleric is the only thing keeping Orah alive. For example, Ravos, Soultender is on the field together with Orah, and Orah is enchanted by Mire's Grasp. In that case, when Ravos is sacrificed, it will trigger Orah, but before the trigger goes to the stack, state based actions are checked and will kill Orah, which gives you another trigger. Both triggers can then be placed on the stack in the order of your choosing, and Orah is a legal target for the Ravos one.
If I have a sac outlet, Is it possible to sac a 5 cmc cleric and then sac orah and return orah with the 5 cmc trigger?
In short, this generally does not work, because most sac oulets let you sac your stuff one object at a time: then, Orah's trigger requires a target, which you must choose BEFORE you get the chance to sacrifice something else (Orah, in this case).