Short series of episodes about television's top executive (11)
I believe the answer is:
ministerial
'executive' is the definition.
(thesaurus)
'short series of episodes about television's top' is the wordplay.
'short series of episodes' becomes 'miniserial'.
'about' is an insertion indicator.
'top' suggests taking the first letters.
The initial letter of 'television' is 't'.
'miniserial' enclosing 't' is 'MINISTERIAL'.
(Other definitions for ministerial that I've seen before include "Maybe cabinet member's" , "about government work" , "Relating to cabinet members" .)