Thorn Birds (2011)

Based on a family that has been torn apart. Both men are unknowingly fathers, separated cruelly from their children.

There's a similar revenge mood, a woman that'll do anything for power and an other that's looking for love and affection...

Both dramas focus more on the female leads and thier negative frenemy relationship. There is one "goody toe shoes" type character and one "evil" character. Both dramas also give off a darker melodrama feel.

Both main men have bitter past love relationships, and unknowingly have children their former lover hid from them. Both struggle with love and acceptance of their past and future life and love.

Secrets galore.
Taking the blame for second female lead (other person).
ML gets bullied, but perseveres and has a happy ending.

Both dramas have a similar plot with differences. Both have an adopted daughter, they try to move on with their lives but the past is blocking their way.