Menials showing necessity? Yes, in a way (7)
I believe the answer is:
lackeys
'menials' is the definition.
The answer and definition can be both people as well as being plural nouns.
Maybe there's an association between them I don't understand?
'necessity? yes in a way' is the wordplay.
'necessity?' becomes 'lack' (I can't justify this - if you can you should give a lot more credence to this answer).
'in a way' indicates anagramming the letters.
'yes' with letters rearranged gives 'eys'.
'lack'+'eys'='LACKEYS'
'showing' is the link.
Can you help me to learn more?
(Other definitions for lackeys that I've seen before include "Servile followers or archaic servants" , "Sycophants" , "Flunkeys" , "Footmen or servile followers" .)