将“可用数据库”下拉列表添加到SSMS中的自定义工具栏

I am creating my own custom toolbar in SSMS. I would like to add the "Available Databases" dropdown that is part of the SQL Editor toolbar to my custom toolbar. But I can't figure out how to add it. It does not appear to be in the command list.I am creating my own custom toolbar in SSMS. I