Barry tries to get a hang of the whole Green Arrow schtick while stopping a gang battle with Diggle in episode 5x09 “Elseworlds, Part 1”.
Oliver zips Barry and Diggle to an empty warehouse to discuss their shared predicament in episode 5x09 “Elseworlds, Part 1”.
Lucifer tracks Renny to a warehouse and follows him inside in episode 1x06 “Favorite Son”.
Jordan talks to Major on her way up to her apartment and realizes her siblings are in bad shape with hunger in episode 4x13 “And He Shall Be a Good Man”.
Chase Graves oversees the execution of Levon and Liv while an angry crowd gathers outside in episode 4x13 “And He Shall Be a Good Man”.
Kara heads the warehouse indicated by Alex's tracker but only finds a trap set by Rick Malverne in episode 2x19 “Alex”.
Source: FloriansEdits — Twitter
Alex confronts Hank Henshaw who is waiting for her with a kryptonite weapon in episode 5x16 “Alex in Wonderland”.