If you would like for users to expire out of a tier after a certain period of time because they haven't done a certain activity, you can create a reset period.

A reset period can be as many days as you like. But the requirement is that the member hit the tier requirement over that period of time.

For example, if the Tier Condition is Spend $500 and the Reset Period id 365 days. That means that that user needs to spend $500 every year for them to stay in that tier. After 365 days, we will check to see if that user spent $500 days, and if they haven't they will be kicked out and have to start working their way back up.