Capital of Lithuania seeming obvious initially, looking back (4)
I believe the answer is:
oslo
'capital' is the definition.
(Oslo is an example)
'of lithuania seeming obvious initially looking back' is the wordplay.
'initially' suggests taking the first letters.
'looking back' is a reversal indicator.
The initial letters of 'of lithuania seeming obvious' is 'olso'.
'olso' in reverse letter order is 'OSLO'.
(Other definitions for oslo that I've seen before include "Norwegian capital" , "Location" , "Capital often frozen" , "foreign port" , "Go solo to European capital" .)