You need to connect one par of coils (or phase) between 1a and 1b and the other to 2a/b. Whether or not you put the coils in series or parallel depends on your drivers/motor. If the a+ and a- are your motor wires(?) then they connect to 1a/b on the driver (doesn't matter which way round, that only reverses the motor rotation direction).


If you're not sure then post what motors and drivers you have so I can help you more precisely.