Segmentation on the customer level gives you many options for filtering by different criteria.
You can select specific customers or leave the field blank and add some of the following additional conditions: customer country, customer group or tag and registration date.
You can filter the subscribers according to their country. You can choose whether a user is "IS" or "IS NOT" from one or more countries. For example, you can choose to segment all users who are from Bulgaria or Greece.
In addition, you can also add specific cities from the Add Condition button to filter users.
The cities that appear in the drop-down menu are the cities that your customers have indicated when ordering and subscribing.
If you want to segment the users relative to the customer group they belong to, you can choose whether the client group "IS" or "IS Not" and specify one or more groups. If you select more than one group, it means that all customers who belong to any of these groups will be assigned to this segment.
See how to create and manage customer groups here.
Register before/after days
Segment your customers according to the time they have registered. You have two options here: filter those who registered "more than" and specify the number of days or hours. The second option is to segment all registered users "in the last" days/hours.
In addition to the above things, you can segment according to the customer's tag. You can add a tag to any customer in his profile and later filter by this criteria.