Site tag in Blox Go

We have 2 papers who share Blox TCMS. We would like to have a site tag selection in Blox Go so that articles submitted by reporters that way end up on the correct website. Currently, articles make it into TCMS but won't make their way anywhere onto the web because there's no way to select which site the article belongs on. Or, if articles are submitted in the CMS Blox Go, they aren't available in TCMS for both papers to use.