I find ObjectFilter doesn't work in SoftLayer.
I even tried the example provided in the SoftLayer webpage here:
https://sldn.softlayer.com/article/object-filters
REST:
List the ID and hostname
of all servers in dal05
https://api.softlayer.com/rest/v3/SoftLayer_Account/getVirtualGuests?objectMask=mask[id,hostname]&objectFilter={"datacenter":{"name":{"operation":"dal05"}}}
When I ran this command, it still returns all the virtual guests, regardless what data center that virtual guest belongs to.