Trace the data back to whatever works in your environment. Your server_s variable is going to contain the sys_id of a record on whatever table that variable references. You can use that sys_id, or a field from the referenced table instead if you pass in something like current.variables.server_s.device_type to a Script Include, but the SI you've shown doesn't look valid for the IP Address table, so you need to start with the end in mind.
1) What is the reference table for the server_s variable?
2) When viewing a record on the cmdb_ci_ip_address table, is there a field which shows a server that you have selected in the variable? If so, what is that field name?
