Using Cold Fusion code you can detect which URL a person is browsing your site with and redirect them to a specific folder. Below is an example that would need to be placed at the top of your default ColdFusion page in the root of your site. (Note: use caution if placing it in an application.cfm file)
<cfif cgi.server_name IS "domain2.com">
<cflocation url="directory2" addtoken="no">
<cfelseif cgi.server_name IS "domain3.com">
<cflocation url="directory3" addtoken="no">
<cfelseif cgi.server_name IS "domain4.com">
<cflocation url="directory4" addtoken="no">
</cfif>
For faster performance, you can use cfswitch syntax as below.
<cfswitch expression="#cgi.server_name#">
<cfcase value="domain2.com">
<cflocation url="directory2" addtoken="no">
</cfcase>
<cfcase value="domain3.com">
<cflocation url="directory3" addtoken="no">
</cfcase>
<cfcase value="domain4.com">
<cflocation url="directory4" addtoken="no">
</cfcase>
</cfswitch>