Not efficiently but you can....
Use two conventional 7805 regulator circuits. Sit one 'on top' of the others +5V output so the bottom one has 0V on it's ground pin and the other has the 5v output from the bottom regulator as it's ground. You now have a stacked regulator 0V, 5V and 10V, it needs more than about 13V at their joined inputs to work properly. Then take the +5V output as your 0V point and you have one 5V above it from the top regulator and the ground from the bottom regulator as your -5V output.
It isn't efficient for several reasons but for low current it may be acceptable. The main problem is the bottom regulator needs to dissipate more heat because of it's higher voltage drop (>8W per Amp) and load variations on the -5V (bottom) regulator can influence the top one. There can also be issues with thermal shutdown as either regulator overheating will influence the heat dissipated in the other.
Use with caution.... but it is possible.
Brian.