Usman, the current schema does not allow that:
site SREL -> site.id
and we don't recommend you to modify this schema as the coding is based on this.
I think you would need to customize the object loc to add a couple of custom attributes like site1, site2... and this
could be the easiest implementation for one location-multiple sites requirement, otherwise you would need BREL
and scripting for that. Thanks _Chi