Loathed touring Croatia's capital, going west in Split (6)
I believe the answer is:
detach
'split' is the definition.
(thesaurus)
'loathed touring croatia's capital going west' is the wordplay.
'loathed' becomes 'hated' (I've seen this in another clue).
'touring' is an insertion indicator (tour can mean to go around).
'capital' says to take the initial letters.
'going west' says the letters should be written backwards (letters heading to the west or left).
The initial letter of 'croatias' is 'c'.
'hated' placed around 'c' is 'hcated'.
'hcated' in reverse letter order is 'DETACH'.
'in' acts as a link.
(Other definitions for detach that I've seen before include "The reverse of 11 Down" , "Split off" , "Separate from, remove part" , "Take away -- the cad (anag)" , "Disengage (something) and remove it" .)