Possibility to have users mapped to existing keycloak groups via ldap federation

i want to have users in keycloak federated by ldap and define some user attribute in ldap to point to an existing keycloak group (for example) .
So no groups must be configured in ldap , only in keycloak . but after synch with ldap the user must be assigned to an existing keycloak group

is this possible (via a mapper) ?