I've been in maintenance foe over 40 yrs. & never thought of trying this.
You have a circuit with a 20 amp breaker. The breaker trips repeatedly.
Disregard that you should be finding the cause.
When a circuit breaker trips, you must find the cause.
A circuit breaker that trips several times can change to "malfunction status" forever, so regardless of finding later the cause for the tripping, the circuit breaker can go bad and needs replacement.
Worst decision is increasing the amp rate of the circuit breaker, because the wiring for 20 amps is 12 awg, and for a 30 amp circuit breaker the wiring is 10 awg, this is for house installation 110v.
You must find the cause of the trips because these can be many, from exposed contact of hot wire with neutral or ground wiring, an overload due to many devices connected to the same circuit, a loose connection in a receptacle of the circuit, a loose circuit breaker in main panel (loose connections cause heat and cause the trip of the circuit breaker), etc.
Don't try to become an expert in series or parallel connection in a simple straight electrical connection. It is against the code and you will end with the need of finding the cause of the problem anyway.
Just find the problem and fix it. And, if it is possible, in case the circuit breaker tripped lots of times, replace it with a new one. A small investment that will maintain safety in your house.