dict_base = {
'key1': {1:'theme1',2:'theme2',3:'theme3'},
'key2':{1:'test1',2:'test2',3:'test3'},
'key3':{1:'some1',2:'some2',3:'some3'}
}
for i in dict_base.keys():
for val in dict_base[i].values():
print(val)
key3 -> [some1,some2,some3]
или
key3: some1,
some2,
some3