I don't know if it's okay to go by description only, but while reading about Undercover, I kept thinking back to Flower of Evil.
Both have a married couple with children, but the male leads have a hidden identity they've been keeping from their wives and others. They both have the female lead learning this identity due to their jobs spinning what they believed of their married life around, however the male leads still do love their wives and want to keep them and their families safe.

While Chicago Typewriter is more historical fiction and Circle is sci-fi, both shows present two stories in one (in Chicago Typewriter it is past and present day, while Circle is present day and future).
In both shows, there is a mystery that happened in the past that the future is trying to figure out. And in both, the viewer is (for the most part) unsure what exactly happened in the past, and everybody's role in it, until it gets revealed.
They both also play with memories.

However, they are still different as they are in different genres and there is a larger time gap in Chicago Typewriter than in Circle. The sequences are not as ordered in Chicago Typewriter as they are in Circle, however the transitions are incredibly smooth.

Bonuses:
- I really liked both the female leads
- Great acting
- The bromances ^.^