Hello,
In this I can not able to select different clock sources only I can enable/disable the peripheral clock.
For S32K3xx clocks are configured in CGM module:
reference manual : Chapter 25 Clock Generation Module (MC_CGM)
And which peripheral goes to which Partition that also not clear
In the clocking chapter you will find which clock is routed where.



I recommend you to read carefully clocking chapter where it is described in details.
Best regards,
Peter