When using filters in a segment, you must indicate the attributes of your audience to search for contacts. 

The fields available in each category may vary for each account. 

Contact Information

Data such as age, gender, country or language

Purchases 

Details about the reservation, such as hotel name, check-in and check-out dates 

Custom Field

Details of custom fields from imported data sheets, your PMS and or booking engine etc

Campaigns

Allows you to filter by the different statuses of a campaign.

Select Segment

You can pre-create a segment and add it to a new one, including or excluding a group of contacts.

Among the most frequent criteria are:

Quantity Criteria

• More than: larger in size / quantity.
• Less than: smaller in size / quantity.
• Equal: the same as.
• Not equal to: not the same as.
• More than or equal to: the same + any larger value.
• Less than or equal to: the same + any smaller value.
• Exists: we have the data / info.
• Does not exist: we do not have the data / info.
• Starts with: letters / numbers at the beginning of the data.
• Ends with: letters / numbers at the end of the variable / data.
• Contains: has in (or as part of) the variable or data.

Date Criteria:

• X days ago: you can enter a number. Ex: 5 days ago (if today is the 10th, it means the 5th).
• X days from now: you can enter a number. Ex: 5 days in the future (if today is the 10th, this means the 15th).
• More than X days ago: you can enter a number. Ex: everything from before 330 days ago to today's date.
• From X days ago: you can enter a number. Ex: everything from 10 days ago to the future.
• After (with calendar): everything from x date.
• Before (with calendar): everything before x date.
• Yesterday - today - tomorrow - in the future.

Status Criteria:

• No status
• Queued
• Sent
• Delivered
• Not open
• Single open
• Not clicked
• Single Clicked
• Rejected
• Undefined
• Undeliverable
• Invalid phone prefix
• Failed
• Bounced
• Subscription cancelled
• Dropped
• Complaints
• Include buyers
• Exclude buyers

Note
Consider that all contacts don't have information in the same custom field. Ex: some may have language and some may not. However, we can always use other fields such as Country to reach the audience.