Adding people to CRM

I am building a CRM and I want to add 100 people to a new list.(list name: TEST.

Once done, i now want to add another 10 to the already existing list (TEST).

My question is, how do I show people already part of the list and also show new 10 people who are supposed to be added to the list.

Should I use a toggle button which reads "add new candidates" and "existing candidates"?

I am building a CRM and I want to add 100 people to a new list.(list name: TEST.

Once done, i now want to add another 10 to the already existing list (TEST).

My question is, how do I show people already part of the list and also show new 10 people who are supposed to be added to the list.

Should I use a toggle button which reads "add new candidates" and "existing candidates"?