Resolution:
1). User Search Filter and Group Search Filters are optional.

a). You can just specify a Group Search Filter as follows but it returns only roles/groups in Admin GUI and does not return users.
You cannot do any authentication as the users are not synchronized.

b). You can  specify a User Search Filter, but it returns only users.
Base DN: dc=tibco,dc=com
User Search Filter: cn=*
Group Search Filter: <empty>

It returns all users in the groups/sub-groups under Base DN but there will not be any roles.

2). Both User Search Filter and Group Search Filter are independent. The result of one does not affect the other.

3). User Search Filter searches for users under "Base DN" including sub-groups. To get more specific type of users you can use "objectclass" attribute to filter out a specific type of users under Base DN.

4). Group Search Filter searches for the groups under "Base DN" including sub-groups. To get more specific type of groups you can use the "objectclass" attribute to filter out a specific type of groups under Base DN.

Filter configuration for LDAP users, roles and groups.