Xtrabackup ignore coonfiguration options in my.cnf

[TABLE=“class: b-layout-table b-layout-table_layout_47-47”]
[TR=“class: b-layout-table__row”]
[TD=“class: b-layout-table__gap”] [/TD]
[TD=“class: b-layout-table__cell b-layout-table__cell_position_r”]
There are three node cluster percona. In section "[xtrabackup] " in the file my.cnf option is specified “databases = db_name” for the change is replicated only on one database. However, when you create a new database with a different name, it appears on other sites. Why option is ignored "“databases”.