Assalamualaikum. what is the best combination of these three names together: Zahran Mashiyat Raif? Do these three names together create a new meaning ?

The two combinations that create something of a meaning are: Zahran Mashiyat Raif means "the blossoming of the willpower of the compassionate one." Mashiyat Raif Zahran means "the willpower of the compassionate one is blossoming"

However, these combinations do not create a meaning unless you add the harakat to them, thus Zahran Mashiyat Raif are three separate words, but in Arabic if you read it as Zahranun Mashiyatu Raifin, then it creates a new meaning. Same for the second combination, it would have to be said as Mashiyatu Raifin Zahranun. Thus these combinations are not like Abdullah, which immediately creates a new meaning from Abd (servant) and Allah (God), which means "servant of God".

So whatever combination you choose is up to you, none of them immediately create a new meaning unless you add the harakat to it. Without the harakat, a person who hears the name will have to guess for himself what the combination means, since the meaning is not immediately clear.