function f1() {
  typeset -n ref1;
  typeset -n ref2=var;
  f2;
  echo "$0: ref1=$ref1 - ref2=$ref2";
  f3;
  echo "$0: ref1=$ref1 - ref2=$ref2";
}

function f2() {
  local var=$0;
  ref1=var;
  echo "$0: ref1=$ref1 - ref2=$ref2";
}

function f3() {
  local var=$0;
  echo "$0: ref1=$ref1 - ref2=$ref2";
}

f1;