In the MMS LDAP Global Role Configuration table please add the following field:

• Property: mms.ldap.group.separator
• Example: ; For OnPrem 1.4 the default is ,. For OnPrem 1.5 the default is ;;
• Description: Each of the global role values may also take a comma-delineated list of groups: For example: "dbas,sysadmins". Therefore, if any group value contains a ",", the separator must be set to a different value. Without this setting, MMS will parse "CN\=foo,DN\=bar" as two elements, instead of the description for a single group.

http://mms.mongodb.com/help-hosted/current/tutorial/configure-for-ldap-authentication/#global-role-configuration