In an international setting, when I used the Difference-in-Differences (DiD) approach to examine the impact of laws on firms (the laws were implemented by many countries, I need to control for country-level control variables. However, I am wondering whether I should control for country-level control variables when studying the impact of laws on a firm's productivity in a single country (e.g., panel data for 100 firms with the time period from 2000 to 2020 - just for example) (using (DiD).

For example, I want to study the impact of anti-corruption on firms' productivity in the retailing industry compared to firms in other industries in Zimbabwe. In this case, whether I need to control GDP, Real interest rate change, corporate tax, Unemployment, import%GDP?