Uses up the budget for writer and director in Titanic, for example (6)
I believe the answer is:
spends
'uses up' is the definition.
('spend' can be a synonym of 'use up')
'writer and director in titanic for example' is the wordplay.
'writer' becomes 'pen' (I've seen this before).
'and' means one lot of letters go next to another.
'director' becomes 'd'.
'in' is an insertion indicator.
'titanic for example' becomes 'ss' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pen'+'d'='pend'
'pend' put within 'ss' is 'SPENDS'.
'the budget for' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for spends that I've seen before include "Gives money to pay for goods" , "Pays money or passes time" , "Lays out (money)" , "Disburses, does not save" , "Uses money or passes time" .)