Correlation Of Vectors Contained In Nested Dictionaries

I have a nested dict with the next structure:

{Cell_name_1 : {KPI_name_1: [value1, value2, ..., valueN], 
                KPI_name_2: [value1, value2, ..., valueN], 
                ..., 
                KPI_name_N: [value1, value2, ..., valueN]}, 
 Cell_name_2 : {KPI_name_1: [value1, value2, ..., valueN], ...}, 
 Cell_name_N : {....}}

I want to check the correlation (I have this method defined already, so it's an auxiliaryfunction) between the vectos contained in the different cells. Let's say:

vector_1 = [64.0, 66.0, 53.5, 52.1, 54.0] #[values from KPI_name_1 from Cell_name_1]
vector_2 = [84.0, 86.0, 63.5, 72.1, 24.0] #[values from KPI_name_2 from Cell_name_2]

correlation(vector_1, vector_2)

I have tried different ways of looping over the dictionaries (normal for loops, classic loops with while and conditions, etc), but I do not find the way to get what I need.

As an example, the code is something like this:

dic_sem = {'16895555': {'KPI_name_1': [64.0, 66.0, 53.5, 52.1, 54.0], 
                        'KPI_name_2': [54.0, 56.0, 23.5, 32.1, 84.0]}, 
           '16894444': {'KPI_name_1': [84.0, 86.0, 63.5, 72.1, 24.0], 
                        'KPI_name_2': [24.0, 26.0, 63.5, 92.1, 84.0]}}

'16895555' and '16894444' are the different Cell_name's.

You can iterate over the dictionary and create a dictionary of the cellnames e.g. KPI_name_1 to a list of lists which contains your vectors

from collections import defaultdict

vectors = defaultdict(list)

#Iterate over the values
for value in dic_sem.values():
    #Create your vectors dictionary
    for k, v in value.items():
        vectors[k].append(v)

print(dict(vectors))

The output will be

{'KPI_name_1': [[64.0, 66.0, 53.5, 52.1, 54.0], [84.0, 86.0, 63.5, 72.1, 24.0]], 
'KPI_name_2': [[54.0, 56.0, 23.5, 32.1, 84.0], [24.0, 26.0, 63.5, 92.1, 84.0]]}

You can then iterate over the values of this dictionary and call correlation accordingly

for value in vectors.values():
    print(value[0], value[1])
    #correlation(*value)

The output here will be

[64.0, 66.0, 53.5, 52.1, 54.0] [84.0, 86.0, 63.5, 72.1, 24.0]
[54.0, 56.0, 23.5, 32.1, 84.0] [24.0, 26.0, 63.5, 92.1, 84.0]