I2C communication on the same board

An alternative to test the I2C Leader-member (master-slave) communication on the same board is to make one of the i2c port(I2C2) as Leader(Master) and any of the available ports (I2C0/I2C1) as member (Slave).

Steps:

Create i2c_slave_init.h and i2c_slave_init.c files. Define a function i2c_slave_init(...) which assigns slave address and slave configuration for a given i2c port. (Refer i2c__initialize function in i2c.c)
Also refer peripherals_init.c to get more info on how I2C2 is initialized.
Call the i2c_slave_init(...) function in your main.c
Connect the SDA and SCL pins of I2C2 with the respective SDA and SCL pins of I2C0/1
Flash the code and try issuing i2c detect command to see if you see a response from member device

You will still need to check a couple of things (CLK, IOPIN registers) before the driver becomes fully functional.