I need a device which have one voltage input(it can be 24V) and 3 output voltages(15V, -15V, 5V).Do you have suggestions?Is there such a device, kit,
IC?

 

What power/current ratings do you need ?

Yes, there are module designs that do this, or you can do this with
regulators, either switched or linear, and charge pumps to get the
negative requirement.

For +/- 15 take a look over here -

https://www.mouser.com/Power/DC-DC-Converters/Isolated-DC-DC-Converters/_/N-brvxe?P=1yx5k7uZ1yxt7dz

+5 tons of vendors have +5 linear, LDO, or switched.

Regards, Dana.