The two groups in Eph. 2:11, but in light of Romans 1:18 thru the end of Romans chapter 3, this side of the end of Acts chapter 7.
In other words, read Acts 7, then Romans 1:18 thru the end of Romans 3.
Then read all of Ephesians 2.
The key wording in all of it is the words Circumcision and Uncircumcision - study out its mention here and there, throughout those various references.
Though this is the view I and other MADS hold.
Some MADs on here appear to hold a slightly different understanding of all that.
Rom. 14:5; Rom. 5:7,8.