First, I will define a numbers function that returns a dictionary, where the keys are integers in the range given as the argument to the function (from start to end inclusive).

numbers() function source code:

```
def numbers(start, end):
dict = {}
for number in range(start, end + 1):
dict[number] = ''
return dict
```

The function can be modified using the decorators with parameters.

My decorator function that modifies dictionary values:

```
def fizzbuzz(number, message):
def decor(func):
def wrapper(*args):
dict = func(*args)
for key in dict:
if not (key % number):
dict[key] += message
return dict
return wrapper
return decor
```

Function numbers() definition with the decorator:

```
@fizzbuzz(5, 'BUZZ')
@fizzbuzz(3, 'FIZZ')
def numbers(start, end):
dict = {}
for number in range(start, end + 1):
dict[number] = ''
return dict
```

Calling the numbers function will not change, e.g. to display dictionary values with keys from 0 to 15:

`print(numbers(0, 15))`

Modification by using a decorator is done behind the scenes.