is it possible to use redis sentinel used for monitoring slave-master ?

[johnny wong]

Say , we have  a master server A, and three slave machines SM1,S2,S3, they are all slave of server A.     but slave SM1 is also server S4 and S5 ’s master. Now we have graphic organization of these servers.

I deployed two sentinel instance on S2, S3 servers to monitor server A .in case of server A crashed , S2 ,S3 will take the master role. 

My question is : is it possible to deploy two sentinel instance on S4,S5 to monitor SM1 server. In case SM1 crashed , S4,S5 would the secondary master role ?