@Abdisalam
as per your query please use drop down option in veronika theme then your user will select particular country, region, city .
<input type="text" name="term" id="term" class="term" placeholder="<?php _e('Country, Region or City', 'veronika'); ?>" value="<?php echo veronika_get_term(veronika_get_session('term'), $prepare['i_country'], $prepare['i_region'], $prepare['i_city']); ?>" autocomplete="off"/>
in original theme Developer has use above code . but as per your query please use below code in item-post.php
For Region :
<?php ItemForm::region_select(osc_get_regions(), osc_user()) ; ?>
For City :
<?php ItemForm::city_select(osc_get_cities(osc_user_region()), osc_user()) ; ?>
For City Area :
<?php ItemForm::city_area_text($prepare); ?>
So please use these code then your user will be select city/regions/city area as per pre defined city/region name by Osclass .
I hope this post will be usefull for you.