I would create array containing max values for each loop and iterate over array.

#!perl -l

@maxvalues = (2, 5, 3);
$input = 3;
my @ids = (0) x $input; # assuming all loops start with 0
while(!$end)
{
  # do something
  print "[@ids]";
  # increase values starting from end of ids array
  $index = $#ids;
  while(1)
  {
    $ids[$index]++;
    if($ids[$index]<=$maxvalues[$index])
      { last }
    else
    { # we reached limit on loop pointed by $index
      $ids[$index] = 0;
      $index--;
      if($index<0) # check stop condition
        { $end = 1 }
    }
  }
}
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