The ASA Site-to-Site VPN configuration examples that I have come across has only one network across both the sites.
If the remote network/site has multiple networks for e.g. DMZ1, DMZ2, INSIDE etc how can it be added via Site-to-Site VPN ASDM wizard.
"If I run a ping from both the ends, should the active tunnels be 1 or 2."
The actual tunnels that transfer the data ie. the IPSEC sa's are unidirectional. So for a site-to-site VPN there are for each connection 2 IPSEC sa's, one in each direction.
For each entry in your crypto map access-list there will be 2 sa's formed so if you ping from Site A and ping from Site B if they are using the same line in the access-list (and they are in your configuration) that will be 2 IPSEC sa's - 1 from A -> B and 1 from B -> A. Which is the same as if you only started the ping from one side.
Can you check on host A that there isn't a firewall running that is blocking incoming echo requests.
I have not seen a specific configuration example with adding multiple networks for IPSEC l2l tunnel via ASDM.
Typically, you would just follow the same process in the below URL but add all the multiple local networks and remote networks that you want to be IPSEC protected.
*Pls rate if it helps*