pFsense: Howto allow access to certain sites for some local users using Aliases?

Dear people,

I have pfSense 2.4.4-RELEASE-p3 installed and with pfblockerNG configured and everything seems to work well. This installation has 3 WANS, 1 Hotspot link and 1 Local NIC. I configured DNSBL and IPv4 blocklists on pfblocker and it blocks even facebook. I need to allow some local hosts (e.g, General Manager, Commercial manager, myself) access to facebook. So my strategy was:

• create an alias for the local IPs and it went well.
• create an alias for the URL websites to be whitelisted (this i could not succeed )
• create a FW outbound rule based on the aliases created
• position these rule before the pfblockerNG FW rules.

My question is how do i create a URL(IPs) alias to achieve this? Whenever i try, i get this error message on saving:

The following input errors were detected: A valid URL must be provided. Could not fetch...