There are a variety of ways to make your hot tub area private, depending on what you want to accomplish.
One way is to add retractable privacy walls. These can be made out of anything sturdy, like metal or plastic, and can easily be set up or taken down as needed. Tall or bushy plants in planters can also provide privacy, as can garden trellises with climbing ivy. Privacy screens can be placed around the entire hot tub area, or just certain parts of it. Finally, if you're willing to put in a bit of extra effort, you could build an inexpensive fence from pallets.