Transfer case and transmission share common housing. As long as both have oil to fill plug on each housing, and its not flowing out, you should be good to take it for repair.
Oil leaks are classified as weep, that's just smearing of oil along the area its weeping from, seep, that's at level it drips on your drive leavening a patch over night, and flow, is when you can visually see the oil running out on the ground with vehicle running. seep and weep are OK to dive to shops for repair.

. Flow, is get it picked up