mm this is just a matter of relativity
if you want 0 and -5 then just make the + of the battery as your circuit common and use the - as the -5 (so no need for any ICs)
if you want -5 ,0 and +5 then you can use a transformer that gives 3 terminals ,,the middle is 0 (common)
if you want to regulate these voltages then yea you need 2 regulators
first reg input is +5 and the common is the 0
second reg input is 0 (circuit common) and the -5 its common
so now you have 3 terminals to use into the circuit
1/ first reg out wich is +5
2/second reg out which is 0
3/ -5 (directly)
this way you did regulate both voltage (5>>0) && (0>>-5)
