You should create 2 subjects:
Subject 1: English for Natives
Subject 2 : English for non-Natives

You should have also 2 groups
Nursery A
Nursery B

There is the following key point to be considered
If several students of Nursery A have English for Natives together with several students of Nursery B group together then you will need a special group of Eng for Natives Group and another group for Eng for non Natives Group.


Example
Nursery A group has 25 students
Nursery B group has 20 students

20 students of Nursery A group take English for Natives and 5 for non Natives
12 students of Nursery B group take English for Natives and 8 for Non Natives

Now the question will be : when they have English class , how many groups will exist in practice
The typical case will be that it will be 3 groups :
English for Natives G1 with 16 (10 of Nursery A + 6 of Nursery B)
English for Natives G2 with 16 (10 of Nursery A + 6 of Nursery B)
and
English for Non Natives with 13 students (5+8)

In such a case the correct set up is
2 subjects are described above
4 groups
- Nursery A with all other subjects included
- Nursery B with all other subjects included
- English for Natives with only English for Natives subject is included
- English for non - Natives with only English for non Natives subject is included

In such a case Student A of Nursery A may be assigned to the following list of Groups-Subjects
Nursery A - Mathematics
Nursery A - Physical Education
Nursery A - Lyrics
English for Natives G1 - English For Natives
etc