Where is the second season of "Danna ga Nani o Itteiru ka Wakaranai Ken", chronologically compared to the first?
The second season interleaves with the events in the first season. 

On the title card roughly in the middle of each episode, it shows the episode number and where it relates to the first season in parentheses below it.


Episode 1 is 7.5 
Episode 2 is 9.5 
Episode 3 is 8.5 
Episode 4 is 11.5
Episode 5 is 12.5


Screenshot from Episode 3:



Screenshot from Episode 4: