In Shopify Flow, it’s now possible to check if a customer belongs to a segment using the new 'Look up customer in segment' action. This feature can be utilized in any workflow involving a customer. The action returns a boolean field 'isMember', indicating membership status, which can be used in conditions or code. For example, you can verify if a customer is in an 'expedited shipping' segment and then tag the order for expedited shipping.
→ Read the full update on changelog.shopify.com