If you are not sure that certain attribute is present, you can add check it’s type for undefined. For example, filter below will match if client-side attribute ‘firmware_version’ is set and equal to ‘1.0.0’
typeof cs.firmware_version !== 'undefined' && cs.firmware_version === '1.0.0'
Assuming following device attributes and their types
The following filter will match all premium subscription devices with positive balance that are located in the USA with firmware version equal to 1.1.0
cs.firmware_version=='1.1.0' && cs.country=='USA' && shared.subscription_plan=='premium' && ss.balance > 0
If you are not sure that all attributes are present for your device, you should use the following syntax that adds all necessary “null” checks
typeof cs.firmware_version !== 'undefined' && typeof cs.country !== 'undefined' && typeof shared.subscription_plan !== 'undefined' && typeof ss.balance !== 'undefined' && cs.firmware_version=='1.1.0' && cs.country=='USA' && shared.subscription_plan=='premium' && ss.balance > 0