[cem] 2-level CEM?

I am considering using Coarsened Exact Matching in order to study the effects of teen mothers' degree type (GED v. HS diploma) on long-term outcomes. In order to sufficiently address my research questions, it seems that I may need two levels of matching: 1) matching those who attained a GED with those who attained a HS diploma (to isolate the effects of degree type on outcomes) 2) matching teen mothers with women who began childbearing after the teenage years (to determine if diploma type effects on later outcomes are the same or different for women who began childbearing during the teenage years v. later) I haven't seen any literature using CEM that conducts two levels of matching as I am proposing. Do you know of literature where researchers have done this and/or do you see any methodological reason for NOT conducting two levels of matching, as I have proposed, when using CEM? Many thanks for any information you're able to pass along.