Some signals may fire off too frequently, or contain too many records. Filters enable you to limit or reduce a signal’s frequency or volume through the use of a second object that is different from, but related to, the one being used for the condition.
Using Filters to Reduce Frequency and Volume
Occasionally the logic you want to use to reduce the signal frequency or volume involves data from another object. Suppose that instead of using the Opportunity Amount, you want to use data off the Account object such as the Account’s Tier.
“Signal me when an opportunity’s stage has changed AND it’s parent Account is Tier 1”
You cannot add the Account Tier field to your condition because your condition is predicated on the Opportunity object, not the Account object. This is where filters come into play. The filter section of the signal enables you to pick a different object and associated fields.
Condition: Opportunity Object “Signal me when an opportunity’s stage has changed”
Filter: Account Object: “Filter the results of the condition to those where the related Account is Tier 1”
When considering a Signal, Conditions are always evaluated first. Only after a condition is found to apply are any filters evaluated to make a final determination on whether to send or suppress the Signal.