Would a JSON path filter not select "uiId"?
For example:
$.[0].uiId to get the uiID and
$.[0].objectId but this does not extract only the integer value in the url.
For retrieving the integer value, you might review the Create Property based on Surrounding Value filter to extract the integer value from the URL. Refer to: Create Property Based on Surrounding Values - DevTest Solutions - 10.1 - CA Technologies Documentation
What happens if the response list has more than one occurrence?
If so,
you may have to iterate over the list... (e.g., count number of items in the list)
iterate over the list with a counting dataset (e.g., from 0 by one until > than count of items - 1 using value INDEX)
filter each elements' value (e.g., $.[{{INDEX}}].uiId, and so on)
deal with each row in the list (e.g., substring out the integer value...)