go to digital recptionist and at sip.uri you can fill in on of the above 3 url number in the diled options.
at inbound routing you can set the time / days for each sip url you created.
This should give you what you want.
When someone calls they will get the ivr. press 1 and the call is sent to username-b2b@pbxes.org and will ring on the extension on ring group you selected.
Outside business hours you can play a message, answering machine or whatever (setup in coming routing)