Splitting 12V power supply into 12V, 9V and 5V outputs
As long as your 12V source supply can support the total current requirements this is a project that requires two switching regulators. 


Feed the input 12V directly to the output 12V loads.
Feed the 12V input to the input of a switching regulator module to convert the 12V to 9V output. Make sure the module is capable of supplying all the 9V load current required. 
Feed the 12V input to the input of the second switching regulator. This module will be used to convert the 12V to 5V output. Make sure that this module can supply at least the 1A that you require.