There are some cases where you may want to use two job portals to display requisitions, for instance if you'd like one page for your external requisitions and another for internal requisitions:
To do so you can use two different job list page settings in order to customise the look and feel of each page, this can be done within:
Recruitment -> Options -> List Page Settings.
This way you can have two separate job portals with two separate sets of application form questions (if you're using custom applications forms this is possible anyway as your form will be selected on the requisition itself rather than determined by the job portal).
Once you have more than one job page setup you can create multiple portal keys within:
Recruitment -> Requisitions -> Other Actions -> Portal Keys
Here you can add new portal keys and choose the job portal template you'd like to display:
Now each portal will display a different portal but if left unrestricted all requisitions which are set to show in portal will display on both pages. To get around this we can first restrict our portal keys to various sites, in my example I've restricted my Internal portal to my Head Office site and the external portal to all other sites, now if I restrict a requisition to the Head Office site it will only display on the internal portal, likewise, if a site is restricted to any other site it will only show on the external portal.