Currently there can be 2 sprints active. You can use JQL "sprint in openSprints()" to filter on all open sprints.
How can you filter on the topmost (first) active sprint, without using the sprintnames itself?
Example:
sprint 1: issues A,B,C
sprint 2: issues D,E,F
result sprint in openSprints() : A,B,C,D,E,F
wanting to get A,B,C