Thanks for your help @noizeburger.
I think I might be able to use the plugin ‘buddypress user account type’, set each type of user to a member level (s2 member for example) or create somekind of tag for each type and create a conditional menu (with perhaps ‘Menu Item Visibility Control’ plugin or s2member) for each type of user once logged in.
Each user would then see the link to ‘hosts’ directory or ‘volunteers’ directory depending on which type of use they are.
The only issue is can I restrict access to the ‘member’s directory’ loop as a whole if someone tried to access this via the url?
