Hello everyone. I am writing my thesis and I am not sure if what I am doing with DID on Stata is correct since I have a moderator.

I am looking at the effect of M&A deal on firm performance, with two different moderator effects that I am looking at differently: the effect of a cross-border acquisition and of the fact that the acquirer is a small firm. Therefore I have all these firm that made deals in 2015 and I am looking at the evolution of a profitability ratio from before (2012 2013 2014) til after (2015 2016 2017). I have a dummy variable for before and after treatment (DummyAfter), a dummy for whether the acquisition was cross border or not (CB) and one for whether the acquirer is small or not (S). I also have a dummy for treatment and control group (Completed=1 and Withdrawn =0)). My fixed effects are industry and year (grouped as "both").

I know the command for a normal DID to see the effect of M&A on the profitability ratio would be: xtreg profitabilityratio DummyCompleted DummyAfter, fe i(both).

How do I add respectively CB and S as moderators to the command? (it would be two different regressions, one with each moderator)

Any help would be much appreciated!