Group Replication with tuned performance Schema settings

Hi, We are using Percona MySql Version 5.7.20-18. We are setting MySql Group Replication for that we need to set Performance Schema on. We want to enable performance schema only for Group Replication related things rest instruments we want to disable for performance schema. Can you please suggest the performance schema settings and its memory settings because once we enable performance schema it starts utilizing lots of memory of the server.