Speak the same language 有共同语言
We’re both obsessed with baseball, so we speak the same language.
Be on the same wavelength
We are the same wavelength and became friends so quickly.
Hit it off （与某人）相处得好，合得来
Jack is pretty friendly. I am sure you guys could hit it off.
Get along with 相处得很好
He gets along very well with his father-in-law.
Birds of a feather
Nancy and Jenny are birds of a feather. You could feel something special between them that leaves you out.