Making another I2c bus

[gizgiz]

How to make two digital pins into I2C pins SDA and SCL

[Kenneth]

Hello,

If you are using the nRF Connect SDK I suggest to check out:
https://academy.nordicsemi.com/lessons/lesson-6-serial-com-i2c/

On a low level what occurs is that the PSEL registers are configured to the pins for the TWI (I2C) instance used, and then the pins will be used after ENABLE register. 

Best regards,
Kenneth