In Adaptive Insights > Modelling > Model Management > Accounts > Accounts Attribute > Click on icon for Create new account attribute (to create an Attribute) and then Click on New Account Attribute Value button (to create an Attribute Value)
*An attribute in Adaptive Insights refers to a tag with a list of possible values that an Administrator defines and then assigns to other dimensional elements, such as accounts. Attributes are used on accounts to group and identify them in useful ways, much like dimensions are used to tag data and levels. Once accounts have been tagged with an attribute, that attribute can be used to select those accounts in reports and in allocation rules.
Users cannot set a parent attribute to an existing attribute.They can only assign a parent Attribute Value to an Attribute Value.