How can a bash code do a return completely while in nested call

How can a bash code do a return completely (as if it returns from main function) when it is being in a third nested function call, in order to get back to shell prompt at once ?

the main function invocation is one which will fully shut down terminal if exit command is given.
tried so many times in vain, one of them:

Code:c(){
local p
#...

[ "$p" = err ] && kill $TID

#...
}

b(){
#...
c
#...
}

a(){
export TID=$$
#...

b
#...
#...
}