Request: a command to do a return completely in normal, ie. not subshell

[Budi]

Can we have a command to 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, in normal, ie. not
subshell?

My main function invocation here will fully shut down terminal if exit
command is given.

c(){
local p
#...

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

#...
}

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

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

b
#...
#...
}