Its all related . We have to bathrooms and shower and bath.

Lately we've been having a lot of troubles with the toilets.
Whenever we do NUMBER 2 in one of the toilets(toilet A), the water in the other (toilet B)starts bubbling when flush toilet A. Then, the water starts rising.. close to the rim..

On TOilet A, the whole water with CRP may come out and spill to the floor. Then,
Water may start coming out of the Bath tub.

And also, our Shower drain also seems clogged sometimes.
And in fact, I think the whole reason why today when using the toilets we had a bad spill of crp is because I used the shower today. That seems to also affect the whole messed up system.

Anyway, seems we have all kinds of interralated problems with t he bathroom piping system. If we are to have it fixed, will they have to break the floor and walls of the bathrom to fix this?

All those fixtures are connected to one main drain which is partially clogged and needs roding. Sounds like you may be on a slab floor, right? There should be a clean out somewhere, doyou know where it is located, it could even be outside but within 24" of the foundation.

seems we have all kinds of interralated problems with t he bathroom piping system. If we are to have it fixed, will they have to break the floor and walls of the bathrom to fix this??
Sounds like a simple clog downstream from tnhe tub to me. This can bne addressed in one of two ways.
1) Snake from the lavatory roof vent, Put out enough snake to reach the base and 20 feet more. **OR**
2)pull the toilet and snake from there.
This should take care of the backups. Good luck, Tom