This may not be the easiest way to do it, but over time there have been many discussions about just this issue. You could read through a few of the discussions.
If you want to hear from the best, here is a link to a video of Dr Gwen Huitt at the MAC & Bronchiectasis Conference at National Jewish Health last year.: https://www.youtube.com/watch?v=3sVHodFi8gY&feature=youtu.be
My own experience, in 18 months on the meds, was that whatever time your body can tolerate is the "best time". I never could take the drugs during the day because the side effects wiped me out. I took them immediately before bed, so by the time the nausea and dizziness hit I was well asleep.
Sue

Thanks for your reply. Do you take all 3 at same time? I used to take Ethambutol and Azithromycin after dinner and Rifampin before bedtime. The video suggest Ethambutol and Azithromycin before breakfast. I started taking those 2 after breakfast and the Rifampin 1 hour before dinner. Trying to feel which will make me feel less tired .

@mai2019 Welcome to Mayo Clinic Connect, a place to give and get support. You are wondering what the best time is to take the big 3 medications?

You will notice that I moved your question to a previous discussion where members like @toni1132 @bluesplashgirl @poodledoc @heathert are already discussing this topic.

May I ask if you have to take all of the medications with food?