I have a 120VAC 15 AMP Circuit that powers 2 receptacles on a back porch and 5 receptacles in a garage on the opposite end of the house. The first receptacle in the circuit is a GFCI on the back porch. This is very inconvenient it one is working in the garage and trips the GFCI on the back porch. Is there any way I can install another GFCI on the same circuit in the garage that will just protect the receptacles in the garage. I could put the garage receptacles on a separate breaker from the back porch but would be more costly.
You should never have more than one GFCI device on a single circuit, as they tend to interfere with each other and cause each other to trip.
I may be wrong, but I also don't think it's technically permitted to have outside circuits on the same line as inside (garage) circuits.
Regardless, your best option - especially since you're probably operating heavy duty equipment in the garage - is to put the garage on its own circuit.