I have a reduced sentence:
"The line graph compares the amount of electricity produced in France using four different sources of power over a period of 32 years."
I think the full sentence is:
"The line graph compares the amount of electricity which is produced in France that uses four different sources of power over a period of 32 years."
So there are 2 relative clauses in this sentence, as I know, a correct sentence has just a relative clause. so please help me understand this.