Be on the same wavelength
Definition 1 of 1
Pro Tip 1/3Informal Use
Used mainly in casual conversations, not in formal settings. 
When chatting with my cousin, it's clear we're on the same wavelength about movies.
Pro Tip 2/3Common Interests
Often implies shared interests or opinions, not just agreement. 
We both love jazz, we're really on the same wavelength.
Pro Tip 3/3Harmony in Teams
Used to describe good team dynamics where members work well together. 
The project succeeded because the whole team was on the same wavelength.