While you can do it, its not very practical
Some hair dryers use over 1500w
So if anyone uses a high wattage hair dryer & someone else tries to plug something in you will kick the circuit off
But if you are set on doing it make sure each bathroom is fed with line & not from the load of the other bathrooms GFCI
Line to 1st bath, this line feed will continue to the 2nd & 3rd bath
In each bathroom install a GFCI
Note if you exceed the wattage for the circuit you will need to go & reset the breaker, not the GFCI
Some hair dryers use over 1500w
So if anyone uses a high wattage hair dryer & someone else tries to plug something in you will kick the circuit off
But if you are set on doing it make sure each bathroom is fed with line & not from the load of the other bathrooms GFCI
Line to 1st bath, this line feed will continue to the 2nd & 3rd bath
In each bathroom install a GFCI
Note if you exceed the wattage for the circuit you will need to go & reset the breaker, not the GFCI